ON MOLLUSCA OF THE WEST COAST OF XORTH AMERICA. 



6bi> 



323. 



324 

 325. 

 326. 



Family Ccecidce. 

 Cdcum crebricinctum, n. s. Large, with aspect oi Elephantulum, but v^ery fine 



close annular sculpture ; plug- subungulate. 8-20 fm. Cp. 

 Ccecum Cooperi, n. s. Small, with 30-40 sharp nan-ow ring-.!. 



Family Turritellidce. 

 Turritella Cooperi, n. s. Extremely slender, with many narrow whirls, c. Cw 

 TurriieUa Jewettii, n. s. Like sanguinea, with very faint scuiptare. 

 Ilesalia lacteola, ? n. s. May be a local var. of the circumpolar laetea, with 

 altered sculpture : distinct, teste Cuming. 

 326 b. 3fesiilia ?var. subplanata. Sculpture fainter : whirls flattened. 



327. Mesalia tenuisculpta, n. s. Very small, slender, whirls rounded, lip waved. 



Shoal-water, Cp. 



Family Cerithiad(S. 



328. Cerithidea sacrata, Gld. E.E.= Califnrfiica, 'Nutt. -^pullata, Gld. Variable in 



shape and sculpture : passes into 31azatlanica, Maz. Cat. no. 395. 



329. ^Bittium filosum, Gld. 'E.E.=Eschrichtii, Midd. Strong, broad, grooved. 

 329J. Bittium ? var. esuriens. Like starved Jilosum, very narrow, adult scarcely 



sculptured. 



330. Bittium attemtatiim, n. 3. Like jjlicatum, A. Ad., or drawn-out esuriens, vnth 



threads instead of grooves. 



331. *Bittium quadrifilatum, n. s. Broad : 4 threads, equal from beginning, coiling 



over strong radiating ribs. 



332. *Bittiutn asperum, n. s. Same aspect : upper whirls with 2 strong and 2 faint 



keels over less prominent ribs. Bch.-40 fm. Cp. 

 SVi. * bittium armillatum, n. s. Same aspect : 3 nearly equal rows of knobs. 



334. Bittium fastigiatum, n. s. Small, slender : apex normal : sutures indented, 



anterior rib strong. 



Family Litorinid(S. 



335. Litorina planaxis, 'Natt. Phi\.=:patula, Gld. E.E. Outside plain; columella 



scooped. 



336. Lihrina Sitchana, Fh.i[.=stdcata, G\d.z=rudis, Coop. Rounded, flat, with spiral 



ribs. Var. modesta, Phil, (pars) has sculpture faint : suhtenebrosa, Midd. . ia 

 perhaps a degraded var. Rocks between tides, Lord; 8-10 fm. Lyall [.^]. 



* These species have so peculiar a nucleus that they can scarcely rank near Ceri- 

 ihiu/i, ur Hissoa: perhaps they are related to Aiabu. T'le nucleus oi esuriens and 



attenuatum has not been seen. 



141 



