334 CALIFOHNIA ACADEMY OF SCIENCES. 



small, flattened, subeqiial, equidistant, revolving ribs, five on tlic upper whorls; interspaces orna- 

 mented by tine, oblique, incremental lines; base of body-wliorl nearly llat, and ornamented with 

 numerous line, revolving lines, which become coarser near umbilicus; suture deeply impressed, dis- 

 tinct; aperture circular; columella somewhat arcuate; umbilicus small, groove-like; outer lip sharp, 

 nacreous layer on inner lijj. 



Dimensions. — Alt. 5.S mm.; lat. S mm.; iletl. 67 degrees. 



Somewhat rcscmhlos Solaridla periDnahU'n^, i)iiL may l)o (li.stiiiguislieti l>y. smaller 

 uinbilicu.s; flutter, liner sculptured l)ase; wliofls less flattened above and finer .sciil[)- 

 tured, both spiral and tfansverse. Dr. Dall prnnomic(!d the Pliocene specimen a 

 variety of M.pupilla. 



Found in Pliocene at Dcadman Island; two specimens, one of which is figured, 

 and is now in the collection of Delos ArnoUl. Found al.so in the Pleistocene at 

 the bath-house, Santa Barbara. 



Living. — Alaska to Catalina Island, rare at latter jilace (Cooper). 



Pleistocene. — Santa Barbara (Cooper; Arnold). 



Pliocene. — San Pedro (Arnold). 



Genus Solariella »S. Wood. 



Shell thin, globular-conical; generally with wide crenated umbilicus; whorls rounded, 

 sculptured; aperture rounded; lip shar]i, smooth. 



Solariella perainabilis Cpr. is a characteristic species. 

 390. Solariella cidaris A. Adanus. 



Plate VII, Fig. 11. 



Margarita cidaris A. Ad., Cpr., Brit. Assn. Rept., 1863, p. 653. Cpr., Ann. Mag. Nat. Hist., 3rd 



Ser., Vol. XIV, 1864, p. 426; Vol. XV, 1865, p. 29. Cooper, 7th Ann. Rept. Cal. St. 



Min., 1888, p. 249 (young); = Solariella oxybasis Dall {fide Cooper, Bull. No. 4, Cal. 



St. Min. Bureau, Part 3, 1894, p. 27). 

 Turcicula cidaris (A. Ad.) Cpr., Trvon, Man. Conch., Vol. XI, p. 331, 1889. 

 Solariella cidaris A. Ad., Williamson, Proc. U. S. Nat. Miis., Vol. XV, 1892, p. 202, PI. XXII, 



fig- 4- 



Shell conical; spire elevated, subacute; whorls six to seven; four upper whorls only slightly 

 convex; lower whorls very convex; surface ornamented witli spiral rows of nodes which grade into 

 nodose ribs on the lower side of the body-whorl; suture deeply impressed; aperture circular; outer 

 lip thin; inner lip and columella enameled, the incrustation completely obscuring the small umbilicus 

 in most specimens. 



Dimensions. — Alt. 40 mm.; lat. 33 mm.; body-vvhorl 26.5 mm.; aperture 13 mm.; defl. 

 66 degrees. 



The specimen described and figured is an exceptionally large one, the average 

 altitude being only 18 mm. Identification by Dr. Dall. 



Hare in the Pliocene; only about a dozen specimens found, and all of these 

 from the Pliocene of Deadman Island. According to Dr. Coo[)er, San Marcial is on 



