LIST OP PLATES. XXXIU 



Page. 



254. Sea Snails, Periwinkles, Drills, and Borers 693 



Fig. 1. Zunatia lieros. See Eeport U. S. Fish Commission. Part I, p. 700. 



Fig. 2. Purpura lapillus. See Eeport U. S. Fish Commission. Parti, p. 698. 



Fig. 3. Purpura la2>illus, banded variety. 



Fig. 4. Keveriia duplicaia. See Eeport U. S. Fish Commission. Part I, p. 700. 



Fig. 5. Ilyanassa obsoleta. See Eeport U. S. Fish Commission. Part I, p. 696. 



Fig. 6. Triiia triviliata. 



Fig. 7. The Whelk, Buocinum undatum. See Eeport U. S. Fish Commission. Part I, p. 699. 



Fig. 8. The PeriTvinkle, Fulger carica. See Eeport tJ. S. Fish Commission. Part I, p. 694. 



Fig. 9. Astyris zonalis. 



Fig. 10. Astyris lunata. 



Fig. 11. Bissoa aouleatus. 



Fig. 12. The Drill or Borer, Urosalpinx dnerea, p. 697. 



255. Various species of clams 703 



Fig. 1. Angulus tener. 



Animal reduced one-half. See Eeport TJ. S. Fish Commission. Part I, p. 677. 

 Fig. 2. The Long Clam, Soft Clam, or Mauninose, Mya arenaria. 



"With animal in extension, reduced to one-half the natural size. 



Fig. 3. Tagelus gibbus. 



With animal, the siphon not fully extended. One-half natural size. See Eeport TJ. S. Fish Commission. Parti, p. 675. 

 Fig. 4. The Eazor Clam, Ensatella americana. See Eeport U. S. Fish Commission. Part I, p. 707. 



With animal extended. One-half natural size. 



Fig. 5. Shows some of the terminal papill£6 enlarged. 



Fig. 6. The Eazor Clam, Ensatella americana. 

 Shell. Natural size. 



Fig; 7. The Ship Worm, Teredo navalis. 

 Enlarged two diameters. 



Fig. 8. The Scallop, Peeten irradians. See Eeport U. S. Fish Commission. Part I, p. 709. 



Natural size. 



Fig. 9. The Bloody Clam, Argina peacata. 

 Natural size. 



256. Various species of clams 703 



Fig. 1. The Quahaug or Little-neoked Clam, Venus mercenaria. 



Natural size. 



Fig. 2. The Quahaug of Puget Sound, Saxidomus NuttalU. 



Natural size of large specimen. Drawn hy J. H. Emerton. 

 Fig. 3. The Gaper Clam of the West Coast, Sohizotheerus NuttalU (Conrad). 



(I.) Specimen of ordinary size, reduced ahout one-fourth in length. The siphons are somewhat contractodi the foot (F) 



expands ahout as usual. 

 (11.) Outline of the left valve of a larger specimen, reduced to the same extent. Drawn from nature by R. E. C. Stearns. 



257. TheGeoduck, or Giant Clam of the Pacific, Glyoimeris generosa 708 



Natural size ; specimens with siphons partly contracted; weight when alive, 6i pounds. Drawn by E, E. C. Steams. 



258. Mussels and Sea Clams , 709 



Fig. 1. The Beach Clam or Hen Clam, Spisula soUdissima. See Eeport U. S. Fish Commission. Part I, p. 708. 



Natural size. 



Fig. 2. The Sea Clam, Cyprina islandica. 

 Natural size. 



Fig. 3. The Black Mussel, Mxjtilus edulis. See Eeport U. S. Fish Commission. Part I, p. 709. 

 Fig. 4. The Black Horse Mussel, Modiola nigra. 



Fig. 5. The Eough Mussel, 71forfto?a ^(icatf/fa. See Eeport TJ. S. Fish Commission. Part I, p. 709. 

 Fig. 6. The Horse Mussel, Modiola modiolus. See Eeport U. S. Fish Commission. Part I, p. 709. 



259. The anatomy of the oyster. (See opposite page for full explanation) 711 



260. Fig. 1. The Eock Crab, Cancer irroratus Say ; male one-half natural size 766 



Fig. 2. Zoea of the same, in the last stage before it changes to the megalops condition; lateral view, 



enlarged seventeen diameters. 

 Fig. 3. Megalops stage of the same, just after the change from the zoea condition; dorsal view, enlarged 



thirteen diameters. 



Fig. 4. The Jonah Crab, Cancer horealis Stimpson ; male, two- thirds natural size 769 



Figs. 5, 6. Terminal joints of the big claws of the same, viewed from the outer side, natural size. 

 Drawings by J. H. Emerton. 



261. The Comroon Crab of the Pacific Coast, Cancer magister Dana; male, somewhat smaller than natural size. . 770 



Drawing by H. L. Todd, from No. 2533, IT. S. National Museum. California, William Stimpson. 



