LIST OF PLATES XIX 



Page. 



254. Sea Snails, Ppriwintles, Drills, and Borers Q'JS 



Fig. 1. Zidiatia hems. See Kcport U. S. Fisli Commission. Parti, p. 700. 



Fig. 2. riirpiiralapillas. See Report U. S. Fish Commission. Parti, p.6D8. 



Fig. 3. Purpura lapilhis, banded variety. 



Fig. 4. Nereriia dupHcata. See Report U. S. Fish Commission. P.art I, p. 700. 



Fig. 5. Ibjauassa obnoleta. See Report U. S. Fish Commission. Parti, p. COG. 



Fig. 6. Tritia trivittata. 



Fig. 7. The Whelk, Buccinum undatum. See Report U. S. Fish Commission. Piirt I, p.G9D. 



Fig. 8. The Periwinkle, Fulgt-r carka. See Report U. S. Fish Commission. Part I, p. 094. 



Fig. 9. Aslyris zonalis. 



Fig. 10. Antijris lunata. 



Fig. 11. Eissoa aculeatits. 



Fig. 12. The Drill or Borer, TJromljnnx riiuna. p. TOT. 



255. Various species of clams 703 



Fig. 1. Angulus tetter. 



Animal reduced one-balf. See Keport 17. S. Fish Commission. Part I, p. 677. 



Fig. 2. The Long Clam, Soft Clam, or Manuinose, JUya urenaria. 



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

 Fig. 3. Tarjchis gihbiis. 



With animal, Iho siphon not fully extended. One-half natural size. See Keport TJ. S. Fish Commission. Parti, p. 075. 

 Fig. 4. The Razor Clam, Eiisalella amcrkana. See Report U. S. Fisb Comiuissiou. Part I, p. 707. 



With animal extended. Onchalf natural size. 



Fig. 5. Shows some of the terminal papillae enlarged. 



Fig. 6. The Razor Clam, EnsaleUa aiiuricana. 



Shell. Natural size. 

 Fig. 7. The Ship Worm, Teredo naralis. 



Eulai'^i^ed two diameters. 



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



Natural size. 



Fig. 9. The Bloody Clam, Argina pexnta. 

 Natural size. 



256. Various species of clams 703 



Fig. 1. The Qnahaug or Little-necked Clara, Venus mercenaria. 



Natural size. 



Fig. 2. The Qnahaug of Puget Sound, Saiidotnus Nuitalli. 



Natural size of large specimen. Drawn hy -T. H. Emerton. 

 Fig. 3. The Gaper Clam of the West Coast, Schizothoerus XiiltaUi (Conrad). 



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



expands about as usual. 

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



2.'i7. The Geodiick, or Giant Clam of the Pacilic, (ilgcimeris geiie.rosa 708 



Natural size; specimens with siphons partly contrai^ted: weight when alive, fi^ pounds. Drawn by R. E. C. Stearns. 



258. Mussels and Sea Clams 709 



Fig. 1. The Beach Clam or Hen Clam, ^j'iauJa soltdissima. See Report U. S. Fish Commission. Part I, p. 70i. 

 Natural size. 



Fig. 2. The Sea Clam, Cifprina isJandica. 

 Natural size. 



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

 Fig. 4. The Black Horse Mussel, Mod'wla nigra. 



Fig. 5. The Rough Mu.ssel, Modiola plicatula. See Report U. S. Fish Commission. Part I, p. 709. 

 Fig. 6. The Horse Mussel, Modiola niodiolus. See Report U. S. Fish Commission. Part I, p. 700. 



2,59. The anatomy of the oyster. (See opposite p.age for full explanation) 711 



2G0. Fig. 1. The Rock Crab, Cancer irroratus Say ; male one-half natural size 706 



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



enlarged .seventeen diameters. 

 Fig. 3, Megalops st.age of the same, just after the change from the zoca condition; dorsal view, enlarged 

 thirteen diameters. 



Fig. 4. The Jonah Crab, Cancer borealis 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. Emertnn. 



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

 Drawing hy H. L. Todd, from No. 2553, U. S. National Museum. California, William Stimpson. 



