NOTICE OF RECENT ADDITIONS TO THE MARINE INVERTEBRATA, OF THE NORTHEASTERN COAST OF AMERICA, WITH DESCRIP. TIONS OF NEW GENERA AND SPECIES AND CRITICAL REMARKS ON OTHERS.

PART IL-MOLLUSCA, WITH NOTES ON ANNELIDA, ECHINODERMATA, ETC., COLLECTED BY THE UNITED STATES FISH COMMISSION.

By A. E. VERRILL.

The species included in the following paper, unless otherwise stated, have been collected by the parties employed by the United States Fish Commission for several years past in exploring the waters and investigating the marine animals of this coast.* This work has been under the immediate direction of the writer, who has personally taken a part in most of the very numerous dredging excursions. The total number of stations dredged or trawled amounts to over 1,200. Among the large number of persons who have taken a more or less important part in these explorations, in connection with the invertebrate department, I may par ticularly mention Prof. S. I. Smith, Prof. A. S. Packard, Mr. Sanderson Smith, Mr. Richard Rathbun, Prof. H. E. Webster, Mr. Oscar Harger, Mr. E. B. Wilson, and Mr. S. F. Clark.

During the last three years Mr. Sanderson Smith has given special assistance in caring for the testaceous Mollusca in the dredging season, and has also been engaged with the writer at various other times in the working up of the Mollusca of Northern New England for publication. Owing to the great accumulation of materials, this will necessarily take much time. In the mean time the following catalogue will afford much useful information as to the additions recently made to our molluscan fauna.

This season, the most interesting and prolific region of our coast hitherto explored was discovered upon the outer bank, or slope, situated from 70 to 80 miles south of Martha's Vineyard, and from 90 to 115 miles south of Newport, R. I.

In September and October three very successful trips were made to this region.

The first of these trips was made September 3 to 5, south of Martha's Vineyard, about 70 to 80 miles (stations 865 to 872), where the depth was from 65 to 192 fathoms. The bottom was mostly fine compact sand, with some mud, and with a large percentage of Foraminifera.

The

*In this article 115 species of Mollusca are recorded as recent additions to the fauna of New England. Of these, 48 species are apparently undescribed (including 23 species just published in the American Journal of Science, for November). The number of species included in this article that are not contained in the last edition of Gould's Invertebrata of Massachusetts is 125. Many other species, not here included, have previously been added by me to those contained in Gould's work. Many of these are enumerated in the author's Preliminary Check List of the Marine Invertebrata of Northern New England, 1879. Many will be found in various articles in the American Journal of Science; others are contained in the Report on Invertebrates of Vineyard Sound, in Part I of the Reports of the United States Fish Commission, 1873.

second trip was made September 12 to 14, nearly south from Newport, 90 to 105 miles, where the depth was from 85 to 325 fathoms (stations 873 to 881). The third trip, October 1 to 3, was to the same region, but somewhat farther west and south, and in deeper water (stations 891 to 895). At all these stations, except 867, a large beam-trawl was used; at 867 a heavy "rake-dredge", of a new form, was used with good

success.

All these stations are situated in the region designated on the charts as "Block Island soundings", and nearly all proved to be exceedingly rich in animal life, the vast abundance of individuals of many of the species taken being almost as surprising as the great number and variety of the species themselves.

In this region the slope is exceedingly gradual till the depth of 75 to 100 fathoms is reached, at about 90 miles from the coast; the slope then becomes much more rapid, but yet not steep, and the bottom is of very fine compact sand, mingled with more or less mud, fragments of shells, and sometimes with small stones,* and generally has a smooth and rather hard surface, well adapted to support a very great variety of animals of nearly all classes. In some places the material is softer mud and sand; in others it is covered with broken shells and great numbers of sponges, hydroids, and worm-tubes.

Many species owe their existence, on these bottoms, to the suitable piaces of attachment furnished by the large tubes of annelids, which formed a marked feature in many of the localities.

In several localities with muddy bottoms (869,879,880,894), we trawled large quantities (several thousands in all) of very singular, large, round, unattached worm-tubes, occupied by a large, undescribed species of Hyalinacia. These tubes are firm and translucent, composed of a tough substance resembling the quills of birds. They are open at both ends, but often have internal septa near the larger end; they are often more than a foot long, and about a third of an inch in diameter at the * These stones, which were common in nearly every haul of the third trip, are of all sizes, from small pebbles up to bowlders 6 inches or more in diameter. They are of various kinds of rocks, like those found in the drift formation along the opposite shores of the mainland and on the shores of Block Island and the eastern end of Long Island. Their presence, so far from land and beneath the edge of the Gulf Stream, can easily be explained by supposing that they have been carried out to sea by the shore ice that forms along these coasts in winter in vast quantities and of considerable thickness. This ice, when it breaks up in spring, is carried out to sea, with its inclosed stones and gravel, by the tides and currents, till it comes in contact with the warmer waters of the Gulf Stream, where its loads of stones drop to the bottom. We have often met with large, loose, and fresh bowlders, sometimes of large size, in various localities, far from land, on muddy bottoms, off the coasts of Maine and Nova Scotia, where they have doubtless been recently dropped from shore ice.

+ Hyalinæcia artifex Verrill, sp. nov. Closely related to H. tubicola of Europe, but much larger, with the buccal segment as long as the three or four following segments; anterior antennæ small, short, rounded, ovate; three median ones subequal, very long, reaching the 15th segment; eyes rudimentary; branchiæ slender, commencing at about the 28th to 30th segment; bidentate setæ with the hook terminal and less curved. Surface opalescent.

larger end, but taper gradually toward the smaller one, and are nearly straight. They may possibly at times stand erect in the mud, but this is doubtful; in most cases they probably lie free on its surface, and the large and powerful annelid inhabiting them probably has the power of dragging them about; otherwise it would be impossible to account for the numerous hydroids, actinians, sponges, &c., which often cover them. On the harder bottoms, in the shallower localities, especially at stations 865 to 867, we obtained great quantities of a very different, unattached worm-tube, composed of bivalve shells, entire and broken, arranged so as to form a strong. flattened covering around a thin silken, central tube. These are made by a pale, opalescent species of Nothria (near N. conchylega), allied to Hyalinacia. In the localities last named we also took large quantities of another very different kind of wormtube, made by another Annelid of the same family, a large species of Eunice or Leodice.* This tube is sometimes half an inch in diameter, more or less attached. irregularly bent, often branched, or with sideopenings at the angles. It is composed of a parchment-like material, and is usually covered with hydroids, sponges, actinians, ascidians, &c. The sand and mud usually contain a large percentage of calcareous Foraminifera, many of which are remarkably large and handsome species, often more than 5 or 6 in diameter. In some of the localities (as at stations 869, 894, and 895) there were, in the mud, very large quantities of large sand-covered Rhizopods (Astrorhiza, Rhabdammina, &c.), which assume a variety of irregularly branched and often rudely stellate forms, but many of them are rod-like, and nearly an inch in length.

Fishes, Crustacea, Annelids, Anthozoa, and Echinoderms, as well as. Mollusca, abounded in new and strange forms. Of many of these species, previously unknown in our waters, thousands of specimens were obtained. At several of the stations, especially at 880, 881, 893, and 894, large numbers of the handsome Mopsea-like coral, Acanella Normani V., were taken; to these many fine specimens of the rare Pecten vitreus were attached, and also several species of Actinians and Annelids. In many of the localities vast numbers of hermit-crabs (Pagurida), of several species, occurred, inhabiting cases consisting of groups of the compound, sand-coated Actinians, mostly Epizoanthus Americanus V. The bases of these originally covered dead shells of Gastropods or Pteropods, occupied by the crabs, but by some chemical process they have, in most cases, wholly removed the substance of the shell, so that the polyp constitutes the entire residence of the crab. Large numbers of huge Actinians, such as Bolocera Tuediæ, Urticina nodosa, &c., oc

*Leodice polybranchia Verrill, sp. nov. A stout species, resembling L. vivida (St.)= L. Norvegica (L.), but the branchia commence on the seventh or eighth segment, and continue to near the end of the body, on at least 120 segments; they have four to six branches; eyes large, round; three median antennæ, long, the middle one longest; tentacles long, reaching beyond the edge of the buccal segment, which is as long as the three following ones; ventral cirri at first conical, those beyond the fourth, short, with large swollen bases.

curred in most of the deeper dredgings. Large quantities of a large, handsome, but very fragile, cup-coral (Flabellum Goodei V.) occurred in the deeper localities, especially at stations 880, 894, 895, but most of the specimens were ruined by being crushed by the great weight of the contents of the trawl. The animal of this coral is bright orange, with

a purple center.

While many of the species of every class obtained here are arctic, or belong to the cold waters found at similar or greater depths on the coasts of Europe and in the Mediterranean, a few genera, like Aricula, Solarium, and Marginella, are related to southern or West Indian forms. A number of the most abundant species of Crustacea and Echinoderms* had already been described from the collections made by Pourtalès, off Florida.

Many free-swimming species, belonging to the Pteropoda and Heteropoda, of which we dredged the dead but perfectly fresh shells, were not previously known to occur so far north. They were associated with others of the same groups which had previously been taken living at the surface along our shores, but they all belong properly to the Gulf Stream fauna.

The frequent occurrence of nearly fresh shells of Argonauta Argo was also a matter of surprise to us, and indicates that this species must often be very common near our coast.

The very large collections of specimens obtained on these three trips have, as yet, been only partially examined, but enough has already been done to prove this region to be altogether the richest and most remarkable dredging ground ever discovered on our coast. The large number of new forms, combined with others previously known only from remote regions, constitute a very distinct fauna, hitherto almost wholly unknown.

A considerable number of undetermined, and perhaps undescribed, shells from these localities are not included in this article.

* A brief account of the Echinoderms obtained by us, with descriptions of several of the new species discovered, has been published by me in the American Journal of Science for November, 1880.

It is only necessary to say here that several of the star-fishes, Ophiurans, and Crinoids occurred in such large numbers as to constitute one of the most conspicuous features of the fauna. The most abundant species were Archaster Americanus V., A. Agassizii V., A. Flora V., Luidia elegans Perriér, Ophiocnida olivacea Lym., Ophioscolex glacialis M. & Tr., Ophioglypha Sarsii Lym., Antedon Sarsii (D. & Koren).

All these species, except the last two, are orange-colored, varying to orange-red. The same is true of Acanella Normani, of most of the Actinians, and of the majority of the crabs and shrimps, as well as of some of the fishes. It seems probable that the prevalence of orange and red colors among the deep-water animals is due to the fact that the luminous rays of those colors are completely absorbed by the thick, overlying stratum of sea-water, and consequently these animals, not being capable of reflecting such bluish and greenish rays as do reach them, would be nearly invisible at those depths beyond which white light penetrates. If this be true, such colors, being protective, may be due to the operation of natural selection, according to the principle so often exemplified in shallow-water animals having colors like their surroundings.

The temperature determinations, owing to the violent motions of the steamer, are unreliable at stations 865 to 872. At stations 873 to 878 the bottom temperature was usually 51° to 53° F.; at 879 to 881 it was 420 to 43° F.; at 893 and 894, it was 40°.

CEPHALOPODA.

The great abundance of Cephalopods in the deep-water localities explored by us is a very interesting and important discovery. Eight species were taken this season. Some of these occurred in large numbers. This collection adds three genera to the New England fauna, two of them new and very curious.

Heteroteuthis tenera Verrill.

Amer. Journ. Science, xx, p. 392, for Nov., 1880 (published Oct. 25).

A small and delicate species, very soft and translucent when living. Body shortish, cylindrical, scarcely twice as long as broad, posteriorly usually round, but in strongly contracted, preserved specimens often narrowed and even obtusely pointed; front edge of mantle with a dorsal angle extending somewhat forward over the neck. Fins very large, thin, longer than broad; the outer edge broadly rounded; the anterior edge extending forward quite as far as the edge of the mantle and considerably beyond the insertion of the fin, which is itself placed well forward. The length of the fin is about two-thirds that of the body; the base or insertion of the fin is equal to about one-half the body length; the breadth of the fin is greater than one-half the breadth of the body. Head large, rounded, with large and prominent eyes; lower eye-lid slightly thickened. Arms rather small, unequal, the dorsal ones considerably shorter and smaller than the others. In the male the left dorsal arm is