less, ranging from forty-two to forty-eight. Head ovoid, with the upper lip conical and more or less angular and obtuse. Eyeless. Caudal ring expanding into a broad, membranous, funnellike pavilion, opening in a slanting manner dorsally and supporting eight divergent rays (see Fig. 1); anterior pair of rays papilliform; the others digitiform

The anterior four rings of the body are provided on each FIG. 1.-Caudal pavilion, with the rays not fully extended, of Dero limosa, viewed side with fascicles of four or five from above. FIG. 2.- A podal stylet. podal stylets, and the succeed- FIG. 3.-4ulophorus vagus within a tube composed of Plumatella statoblasts, maging rings with fascicles of three nified about six diameters. FIG. 4.-Spadeor four stylets. The latter rings like podal stylet and bristle. FIG. 5.-Side view of the head of Pristina flagellum. are also provided more dorsally FIG. 6.-Posterior extremity of the body of on each side with additional the same with its three caudal appendages. fascicles mostly of a single stylet and a simple bristle. Stylets sigmoid with a median shoulder, and ending in a furcate hook (see Fig. 2).

Another of the little worms allied to the genus Dero, was collected together with some Plumatella scraped from a log in a ditch of the meadows below Philadelphia. It was in the latter part of September, and the water collected contained a great many detached statoblasts or winter eggs of the Plumatella. The worm first attracted my notice from the fact that it occupied a tube composed of the Plumatella eggs cemented together, and which it dragged about in the same manner as the larva of the Caddis does its case (see Fig. 3). The only worm of European waters which

appears to approximate this one, and which may prove to be the same, was described and figured a century and a quarter ago by the portrait painter naturalist, Rösel von Rosenhof, as the little supple water-serpent with two fork prongs-" das geschmeidige Wasserschlänglein mit zwey Gabelspitzen" (Insecten Belustigung, Nürnberg, 1755, Th. 3, 581, Tab. xc11, Fig. 8-16). In character and habits it so closely accords with the genus Aulophorus of Schmarda (Neue wirbellose Thiere, 1861, 11, 9), that I have referred it to a species of the same. Schmarda describes two species, A. discocephalus of Jamaica, and A. oxycephalus of Ceylon.

Our species I propose to name Aulophorus vagus. Its characters are as follow: Body compressed cylindrical, transparent, with red blood and yellowish-brown intestine. Single individuals of the third of an inch or more in length, composed of twenty-four to thirty-five rings. Head ovoid, extending as a conical upper lip, very mobile and changeable in form, obtuse or sub-acute, and minutely hirsute. Eyeless. Caudal ring contracted and furnished with a pair of long divergent digit-like appendages, which are straight or slightly incurved, blunt and minutely hirsute. Anal aperture surrounded by a rosette of half a dozen prominent, blunt, conical papilla. The four rings succeeding the head furnished on each side with fascicles of seven to nine podal stylets; the succeeding rings, except the last, with fascicles of five to six podal stylets, which are shorter than the former. Podal stylets sigmoid, with a median shoulder, and ending in a furcate hook (Fig. 2). The same posterior rings furnished dorso-laterally with fascicles consisting each of usually a single moderately long bristle, and a single, nearly straight stylet, ending in a spade-like expansion (see Fig. 4).

Pharynx capacious, extending into the fifth ring, and narrowing into an œsophagus which ends in the intestine within the ninth ring. Generative organs unobserved. Worm of three to five lines in length, or more, according to its degree of extension. Living in a tube of its own construction which it drags about with it. The tube is composed of a transparent cement or basis incorporated with various materials, such as vegetal particles, sand, dirt, diatoms, spongilla spicules, etc. In creeping about among aquatic plants, Lemna and Wolffia, the worm stretches in such a manner that one-third of the body extends from the fore part of the tube, while the forked caudal extremity remains projected

from the back end. The worm moves in jerks, alternately extending the fore part of the body and projecting the podal fascicles forward and hooking into the surface on which it is creeping, and then contracting the fore part of the body and dragging along the back part enclosed within the tube. Frequently the motion is aided by the eversion of the pharynx, so as to form a disk or sucker which adheres to surfaces, like that of a leech. The movements occur in quick succession, so that the worm creeps about quite actively. At times the worm will double on itself and in this way pass through its tube and reverse its direction. At times too it will leave its tube and creep about without one. The papillæ of the anal aperture are clothed with vibratile cils, which produce an active current inwardly as observed in Dero.

Another little Naiad with conspicuous caudal appendages, in all other respects except in the possession of the latter, resembles Pristina, and I have therefore regarded it as such, with the name of Pristina flagellum. Its characters are as follow: Body compressed cylindroid, transparent, with red blood. In a specimen one-fourth of an inch long and exhibiting evidence of division. into two individuals, there were about sixty rings, or thirty to each division. Head conical and prolonged into a digit-like upper lip (Fig. 5). Eyeless. Caudal ring furnished with three long digit-like, blunt appendages, trailing behind; the lateral pair nearly twice the length of the intermediate one (Fig. 6). Podal stylets in fascicles of four, on each side ventrally, to all the rings except the terminal ones; sigmoid with a median shoulder and ending in a furcate hook. Bristles to all the rings dorso-laterally, except the terminal ones, in fascicles of three to six.

Length of worm, 6 to 7 mm.; breadth 0.3 mm.; length of digit-like upper lip from the mouth, 0.25 mm.; length of lateral caudal appendages, 0.75 mm.; of intermediate one, 0.375 mm. ; length of bristles, 0.25 to 0.375 mm. Creeping among aquatic plants in the ponds of sphagnous swamps, New Jersey and Pennsylvania.

AMERICAN WORK IN THE DEPARTMENT OF RECENT MOLLUSCA DURING THE YEAR 1879.

IT

BY WILLIAM H. DALL.

has not been practicable for the writer to emulate the Zoological Record in minuteness of detail, however desirable that course might have been for some reasons. It is possible that some minor papers may have been overlooked from not having been sent to the Smithsonian Institution or the writer during the year, but it is not likely that anything of importance has escaped notice. It was open to the writer to make this article a mere catalogue or a review of work done. He has chosen the latter as the most useful course, and has freely expressed his opinions in regard to the papers enumerated. It is a subject for regret that, in America, among those who are interested in Mollusca especially, the veterans are passing away and few come to fill their places. This is perhaps due to the absence of any satisfactory text book, the condition of the nomenclature and the inferior po'sition occupied by the groups in most manuals of zoology, so far as treatment is concerned. We may hope that the laboratories of Prof. Alexander Agassiz and of the Johns Hopkins University, with the other seaside summer schools, may produce good fruit in this direction. There is certainly no department as a whole in which more work must be done of all (except merely descriptive) kinds, before the science can be put on a satisfactory footing.

Even under the present adverse circumstances, a creditable amount of good work has been done in several directions, and we may reasonably expect that succeeding years will be hardly less fruitful. The harvest truly is plenteous but the laborers are few.

General Works on Mollusca.-But one publication which can claim to be of this nature has appeared in America in 1879. This is a "Manual of Conchology, structural and systematic, with illustrations of the specics," by Geo. W. Tryon, Jr.; 8vo, Philadelphia, the author, 1879, et seq. Of this, three parts of Vol. 1, Cephalopoda, have come to hand, and include 192 pages of text and seventy plates. The scope of the work is thus stated by the author: It is to be a "Conchological manual, which, while more comprehensive than any similar work hitherto published, shall be so condensed in text and illustration, that it may be issued at a much more moderate price. It will include, in systematic

order, the diagnoses of all the genera and higher divisions of the Mollusca, both recent and fossil, and the descriptions and figures of all the recent species, together with the main features of their anatomy and physiology, their embryology and development, their relation to man and other animals, and their geological and geographical distribution." "Each part will be complete in itself, Part I will contain the Cephalopoda; the Muricidæ will follow." "Only 250 copies will be published." It is but fair to say that the parts of this gigantic undertaking, which have so far appeared, comprise the results of a surprising amount of industry.

Anatomy and Development.-Perhaps the most important papers which have appeared in this department during the year, are those of Prof. W. K. Brooks in the "Scientific Results of the Session of 1878, Chesapeake Zoological Laboratory;" 8vo, 170 pages, 13 plates, Baltimore, Johns Hopkins University, 1879.

Of the two papers referred to, the first on "The Development of Lingula and the systematic position of the Brachiopoda,” is the most extended (35--112 pp., 6 pl.) and important. The first portion is devoted to a description of the features of the embryos of Lingula (Glottidia) pyramidata Stm., with a review of previous investigations on the same subject. The second part reviews the "Bearing of the development of Lingula upon the systematic position of the Brachiopoda." The several very diverse views of different authors are discussed in the light of the new facts previously set forth, and especially that theory held and expounded with so much energy and wit by Prof. E. S. Morse, that the Brachiopods were (1) Annelids or (2) "Vermes."

The important contributions to our knowledge of the early stages of Brachiopods, made by Prof. Morse in the past, entitle any views of his to respectful consideration, such as is here accorded to them, but with the result of dismissing the first (which indeed had never been accepted in literal fashion by any naturalist of standing except Prof. Morse) very briefly, and for the second, concluding that "the Brachiopods then are 'Vermes' in the same sense that the Echinoderms, Mollusca, Tunicates and Vertebrates are" (1. c. p. 102), and reiterating views expressed in 1876, to the effect that, "as soon as we recognize that the Lamellibranchs are not to be regarded as typical Mollusca, and that all of the latter are to be traced back to a 'Veliger,' all difficulty seems to disappear, and it becomes plain, not only that Mollusca and Mol