328 rALiKoHNiA A( ai>i:my ok sciences. 



Sliell conical, tliiii; spire elevated, suliacutc; whorls live or six, llat; ornaineiitaiiLiii consists 

 of smooth keel on anterior part of whorl and row of nodes on posterior part next to suture; flat space 

 between these two smooth; both keel and ll.it surf.ice nodose on anterior |).irt of body-whorl; suture 

 very ilee]) and narrow; boily-whorl acutely anguhiteil at base; base sliyiitiy convex, ornanitntcd with 

 several alternating large and small nodose spiral ridges; aperture ir.ipi-zoid.ii; outer lip thin, bulging 

 below; columella incrusted, anil having two plications. 



IJinit-nsioiis. — .Alt. 19 mm.; lat. 16 mm.; ilefl. 70 degrees. 



Distiiii;iiisli,ililc from tlic Oa/linxtmti/i' l)y the (Ici'p, miiiiow .suture, lai'gu 

 :i|U'fliir(', willi l)iilj;iiin' lower |i:irl of (inter lip, iiml pliciiled (•(iliiiiiell;i. 



Foiiiicl ill IMidC'c'iie of DL'iulinaii l-laiid; one specinu'ii fnun lower San Pedro 

 series of Deadmaii Island. 



LiriiKj. — Montefej (Cooper): San Pedfo (Raymond). 



Pleistocene. — Santa I'arhara; San Pcdfo (Cooper): San Pedro (Arnold). 



Pliocene. — San Pedro (Arnold). 



Genus Phorcus Risso. 



Shell conoidal, umbilicated; umbilicus cylindrical or infiiiulibulironn; whorls frequently tuber- 

 culated above ami with channeled suture; columella sometimes terminating in a tubercular tooth. 



Phorcus viayufi Linn, is a characteristic species. 



379. Phorcus pulligo Murtj/n. 



Trochus ptdligo Mai^t., Univ. Conch., I'l. LXXVI, 1784. Piui.ii'Pi, Conch. Cab., p. 84, PI. XV, 



fig. 3. P'lscnF.K, Coq. V'iv., p. 232. PI. LXXX, fig. i. 

 Phorais pulligo Makt., Ci'R., Brit. Assn. Rept., 1863, p. 653. Cooper. 71I1 Ann. Rejit. Cal. Si. 



Min., 1888, p. 259. 

 Chlorosloma pulligo Mart., = C. niarcidus GiAi.{/ide Trvon, Man. Conch., Vol. XI, j). 171, 



PI. XXVI, fig.s. 23, 24, 25, 1889). 



Shell broadly conical; whorls five, flat, but .somewhat obsoletely ribbed or bluntly nodose 

 in most specimens; surface shows extremely oblique lines of growth; suture distinct but not much 

 impressed; base flat anil smooth, except for faint incremental lines; ajjerture subovate; lips not 

 thickened; umbilicus smooth, round and effuse. 



Dimensions. — Alt. 18 mm.; lat. 22 mm.; defl. 78 degrees. 



Tlii.s shell is often confii.sed with Chloroatoma moiifercjji, hut may be distin- 

 giii.shed from thai species hy its gradually expanding iiinbilicus, greater deflection, 

 and lack of spiral .sculpture. Specimens of thi.s species were identified by Dr. Dall. 



Ilather common in the u))[)er San Pedro series of Crawfish George's. The 

 specimen figured is from the upper San Pedro series at Crawfish George's, and is 

 now in the collection of Delos Arnold. 



Living. — Sitka to San Pedro (Cooper.) 



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



