EXPLANATION OF PLATE VII. This plate, drawn on stone under my own direction, is intended to present, as faithfully as possible, the characters of some of the more rare and critical shells of the Canadian Post-pliocene. Fig. 1. du-Loup. Fig. 2. Fig. 3. Astarte Banksii-A full-grown specimen of the ordinary type. Riviere Astarte Laurentiana--An average full-grown specimen. Montreal. Fig. 4. Astarte Elliptica-A specimen with the ribs extending nearer to the ventral margin than usual. Portland, Maine. Fig. 5. Buccinum tenue-Full-grown specimen. Sculpture enlarged. Fig. 6. Buccinum cyaneum-Full-grown specimen. Riviere-du-Loup. 6a— Sculpture enlarged. Fig. 7. Buccinum undulatum-(Var. of undatum)-Immature shell, broken at lip. Riviere-du-Loup. 7a-Sculpture enlarged. Fig. 8. Buccinum glaciale-Tuberculated variety. Riviere-du-Loup. Sculpture enlarged. Fig. 9. Buccinum glaciale-Smooth variety. ture enlarged. 8a Riviere-du-Loup. 9a-Sculp Fig. 10. Buccinum ciliatum (Fabricius, not Gould)-Smooth variety, somewhat decorticated. Montreal. 10a-Sculpture enlarged. Fig. 11. men. Buccinum ciliatum-(Fabricius, not Gould)-Small but mature speciRecent Murray Bay. Fig. 12. Buccinum Grænlandicum-Adult specimen. St. Nicholas. 12a Sculpture enlarged. Choristes elegans—(Carpenter)—Adult specimen. Montreal. 13a Sculpture enlarged. Fig. 13. Fig. 14. Capulus commodus-Pt. Levi, Quebec. THE CANADIAN NATURALIST AND Quarterly Journal of Science. THE POST-PLIOCENE GEOLOGY OF CANADA. By J. W. DAWSON, LL.D., F.R.S., F.G.S. SUB-KINGDOM MOLLUSCA. Introductory.-In preparing this, the largest and most important part of my catalogue, I have to acknowledge my obligations to Dr. P. P. Carpenter, for his kind aid in comparing all the more critical species of shells, and in giving me his valuable judgment as to their relations and synonymy, which I have in nearly every case accepted as final. I am also indebted to Dr. Carpenter for all the notices of West-coast shells. To Mr. J. F. Whiteaves, F.G.S., I am indebted for reviewing the Polyzoa and comparing them with Smitt's Norwegian catalogues, and also for many valuable facts as to shells obtained in his recent dredgings in the Gulf of St. Lawrence. To Mr. J. Gwyn Jeffreys, F.R.S., and Mr. R. McAndrew, F.R.S., of London, my grateful acknowledgments are due for aid and information, and also for the opportunity of comparing my specimens with those in their collections. My comparisons with recent species have been made to a great extent with specimens dredged by myself, in the Gulf of St. Lawrence, and especially at Murray Bay, where the marine fauna seems to be more nearly related to that of the Post-pliocene VOL. VI. Q No. 4. |