60 



747 Chrysodomus tenebrosus Hancock. 

 Circumboreal — Lapland — Sitka, Alaska. 



748 Chrysodomus verkruzeni Kobelt. 

 Vancouver Island. 



749 Clathurella crystallina Gabb. 

 Catalina Island, California, 40 fms. 



750 Cochliopa rowellii Tryon. 



Near Baulinas bay, Marin Co., Cal. (Jos. Rowell), not Clear 

 Lake (see Nautilus 20:10). Panama? 



Shell depressed, wider than high, whorls 3%, regularly con- 

 vex, rapidly enlarging; spire small, slightly elevated, apex acute, 

 sutures well marked; base convex, except that region around um- 

 bilicus is flattened and inclined toward the axis, its outer boun- 

 dary marked thus by an angle; umbilicus small, very distinct; 

 aperture half ovate, labrum well rounded, thin, labium slightly 

 rounded, thickened, elevated from body whorl forming an acute 

 angle with the labrum above, and not impinging on the umbilicus. 

 Color yellowish-green. Operculum paucispiral. Height 2 x / 2 , 

 larger diameter 4, smaller 3 mm. 



751 Columbella baccata Gaskoin. 



San Pedro, Cal.? — Cape St. Lucas and Gulf of California. 



752 Columbella chrysalloidea Carpenter. 

 San Pedro to San Diego, Cal. 



753 Columna ramentosa J. G. Cooper. 



Base of Sierra de Lagunas, Lower California. 



754 Var. abbreviata 

 High on Sierra Lagunas. 



755 Crassatella marginata Carpenter. 

 Catalina Island; San Diego, Cal. 



756 Crenella decussata Montagu. 



Circumboreal — Finland to Scotland — south to North Carolina; 

 Catalina Island, California, 10-40 fms. 



757 Crucibulum tubiferum Lesson. 



Santa Barbara, Cal., to Chili, South America. 



758 Cryptobranchia concentrica Esch. 



North Japan (Stimpson) ; throughout the Aleutian Islands, 

 along the southern coast of Alaska (Dall) ; British Columbia; 

 Puget Sound. 



Dall, U. S. Na. Mus. pr 1:334 (1878). 



759 Var. instabilis Dall. 



Dall, U. S. Na. Mus. pr 1:335 (1878). 



?Crytobranchia instabilis Dall Am J Conch 5:145 t 15 f 6 

 (1869). 



Aleutian Islands (Dall). 



760 Crytobranchia alba Dall. 



Dall, Am J Conch 5:145 t 15 f 3a-4 (1868). U S Na Mu pr 

 1:335 (1878). 



761 Crytochiton stelleri Middendorf. 

 Kamtschatka and Alaska to Monterey, Cal. 



762 Crytodon flexuosus Linne. 



Circumboreal — Finland to Canary Islands — North Pacific 

 ocean to Catalina Island, California, 120 fms. England. 



763 Crytodon sericatus Carpenter. 



Vancouver Island to Catalina Island, California. 



764 Cytherea (Amiantis) callosa Conr. 

 See No. 118.) 



