NORTHWEST COAST MARINE SHELLBEARING MOLLUSKS. 161 
TRUNCATELLA STIMPSONI Stearns, 1872. 
Proc. Cal. Acad. Sci., vol. 4, p. 248, pi. 1, tig. 5. 
Catalina Island, California, to Magdalena Bay, Lower California. 
Family SYNCERATIDAE. 
Genus SYNCERA Gray, 1821. 
SYNCERA TRANSLUCENS Carpenter, 1864. 
Suppl. Rep. Brit. Assoc., 1863, pp. 613, 657 ; Proc. Cal. Acad. Sci., vol. 3, 
p. 219. 
Vancouver Island to Lower California. 
Family CAPULIDAE. 
Genus CAPULUS Montfort, 1810. 
CAPULUS CALIFORNICUS Dali, 1900. (Plate 15, fig. 6.) 
Nautilus, vol. 13, No. 9, p. 100. 
San Pedro to San Diego, on Pectens. 
Genus PILISCUS Loven, 1859. 
PILISCUS COMMODUS Middendorff, 1851. 
Sibirische Reise, vol. 2, p. 214, pi. 17, tigs. 4—11. 
Arctic Ocean to Pribilof Islands, Bering Sea, and the Okhotsk Sea. 
Family HIPPONICIDAE. 
Genus HIPPONIX Defrance, 1819. 
HIPPONIX BARBATUS Sowerby, 1835. 
Proc. Zool. Soc., p. 5. — Teyon, Man., vol. 8, pi. 40, figs. 2-3. 
Crescent City, California, to Panama and the Galapagos Islands. 
HIPPONIX SERRATUS Carpenter, 1857. 
Mazatlan Cat., p. 296. — Teyon, Man., vol. 8, pi. 100, fig. 40. 
Monterey, California, to Panama. 
HIPPONIX ANTIQUATUS Linnaeus, 1767. 
Syst. Nat., ed. 12, p. 1259 . — Teyon, Man., vol. 8, pi. 40, figs. 93-97. 
Crescent City, California, to Panama and the Galapagos Islands. (P-eyi^c.. 
HIPPONIX ANTIQUATUS CRANIOIDES Carpenter, 1864. 
Ann. Mag. Nat. Hist., ser. 3, vol. 14, p. 427. — Teyon, Man., vol. 8, pi. 40, 
fig. 6. 
Vancouver Island to San Pedro, California. 
HIPPONIX TUMENS Carpenter, 1865. 
Ann. Mag. Nat. Hist., ser. 3, vol. 15, p. 180.— Teyon, Man., vol. 8, pi. 40, 
fig- 
Crescent City, California, to San Diego. ColI . , 
