302 CALIFORNIA ACADEMY OF SCIENCES. 



lower 8:111 IVdro isories of Dt'iulmun Islaml; toiiiul also in lliu lower San Pedro 

 series at San Pedro; and in the Pliocene of Deadman Island. 



Living. — Sitka; San Diego (Cooper). 



Pkistocene. — San Nicolas Island; San Diego (Cooper): San Pedro (Arnold). 



333. Littorina scutulata (louUl. 



Litlorina scutulata Gi.i)., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 83; Wilkes' Expl. Exped., 



Vol. XII, p. 200, fijj. 241, 1852. Cpr., Brit. Assn. Rept., 1863, p. 656. Tryon, Man. 



Conch., Vol. IX, p. 250, PI. XLV, fij;s. 98-103, 18S7. Cooper, 7th Ann. Rept. Cal. 



St. Min., 1888, p. 246. Keep, West Coast Shells, p. 68, fig. 52, 1892. Williamson, 



Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 205. 

 Littorina plena Gld., Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1849, p. 84; Wilkes' E.xpl. Exped., 



Vol. XII, p. 201, fig. 236, 1852. 



Shell small, conical; spire elevated, subacute; whorls four, very slitjhtly convex, the last one 

 ventricose and slightly angulated; sculpture consists of numerous nearly obsolete, spiral stri;e, and 

 fine, oblique, incremental lines; aperture ovate; outer lip thin, lower part effuse; inner lip incrusted, 

 effuse; color reddish brown. 



Dimensions. — Alt. 10 mm.; lat. 6 mm.; ajierturc 5 mm. x 3 mm.; defl. 48 degrees. 



All the specimens from the Pleistocene that have heen examined show a 

 characteristic reddish brown color. Several specimens identified by Dr. Dall; among 

 them two which were marked "variety," but which have been included in this species 

 for lack of constant varietal differences. 



Found in the lower San Pedro series at Deadman I.slaiui and San Pedro; and 

 ill tlie upper San Pedro series at Los Cerritos, Crawfish George'.s, San Pedro, Long 

 Beach, and Deadman Island. Found in the Pleistocene! at Barlow's ranch, Ventura; 

 and at Pacific Beach and Spanish Bight, San Diego. 



Living. — Monterey to San Diego (Cooper). 



Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; Ventura; San 

 Diego (Arnold). 



Genus Lacuna Turton. 



Shell turbinated, thin; aperture semilunar; columella flattened, with an umbilical fissure. 



Lacuna pallidida Da Costa is a characteristic .species. 



334. Lacuna compacta Carpenter. 



Lacuna .? var. compacta Cpr., Brit. Assn. Rept., 1863, p. 656. 



Lacuna {? solidula, var.) compacta CPR., Ann. & Mag. Nat. Hist., 3rd Scr., \'ol. XIV, 1864, p. 429. 

 Tryon, Man. Conch., Vol. IX, p. 266, PI. L, fig. 71, 1887. 



Shell small, thin, compact; spire elevated, subacute; whorls four, slightly convex; body- 

 whorl prominently angulated at base; suture impressed, distinct; aperture ovate; outer lip not effuse^ 

 thin; inner lip slighdy effuse; chink very small, almost obsolete; surface faintly marked with very 

 fine incremental lines. 



Dimensions. — Long. 6 mm.; lat. 4 mm.; aperture 3 mm. x 2 mm.; defl. 60 degrees. 



