ARNOLD — THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDRO. 313 



352. Hipponyx turaens Carpenter. 



Hipponyx lumens Cpr., Brit. Assn. Rcpt., 1863, p. 654; Ann. & Mag. Nat. Hist., 3rd Ser., 



Vol. XV, 1865, p. 181. 

 Capulus himens Cpr., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 232. 



Shell of mediinn size, tumid, with oval base; ape.x distinct, small, sharp, curved to right 

 side, raised above margin; surface sculptured by numerous sharp, distinct, raised radiating lines and 

 less j)roniinent lines of growth, which give the radiating lines a slightly gfranulose appearance; 

 a])erture oval, slightly effuse, and finely crenulated on outer border. 



Dimensions. — Long, (including apex) 11.5 mm.; lat. 10 mm.; alt. 5 mm. 



Distinguishable from //. nntiqiiatvs by its rather faint, regular sculpture, of 

 which tiic railiatiiig lines arc iniicli more piominent tiiaii the concentric. 



One si)eciinen from the lower San Pedro series of Deadman Island; also found 

 in lower San Pedro series at San Pedro; and in the ujiper San Pedro series at Dead- 

 man Island. Found also in the Pleistocene at Pacific Beach, San Diego. 



Living. — Monterey to San Diego and Islands (Cooper). 



Pleistocene. — San Pedro (Cooper; Arnold): San Diego (Arnold). 



Family LXXVlll. NATIClDiE. 

 Genus Natica {Adanson) Scopoli. 



Shell subglobular; spire slightly elevated; aperture half round; a spiral columellar callus 

 entering the umbilicus. 



Natica canrena Linn, is a characteristic species. 



Subgenus Cryptonatica Dull. 



A'aticas with smooth calcareous operculum and an umbilicus entirely and smoothly filled 

 with callus. 



Type, Nnticn clmisn Brod. & Sowb. 



353. Natica (Cryptonatica) clausa Broderip <fc Sowerby. 



Platk X, Fig. 18. 



Nalica c/ausa Hkod. & Sby., Zool. Jour., Vol. IV, 1829, p. 360; Zool. Beechey's Voyage, p. 136, 

 PI. XXXIV, fig. 3; PI. XXXVII, fig. 6, 1839. Cpr., Brit. Assn. Rept., 1863, p. 661. 

 Gabb, Pal. Cal., Vol. II, p. 77, 1869. Tryon, Man. Conch., Vol. VIII, p. 30, PI. IX, 

 figs. 65, 67-69, 73, 1886. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 253. Keep, 

 West Coast Shells, p. 46, 1892. 



A^atica russa C.i.n., Proc. Bost. Soc. Nat. Hist., Vol. VII, 1859, p. 43; Otia, p. 109, 1862. Cpr., 

 Brit. Assn. Rept., 1863, p. 586. Cooper, Bull. No. 4, Cal. St. Min. Bureau, Part 3, 

 1894, p. 29. 



Shell of medium size, ovate-globular; spire only slightly elevated; whorls four, evenly 

 conve.x, though sometimes slightly shouldered; surface smpoth except for fine incremental lines; 



( 40 ) April 28, 1903. 



