ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 



bbb 



Family Ccecides. 

 S22. Ca-cum crebricinctum, u. s. Large, with, aspect oi Elephantulum, Lut very fine 

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



323. Ccecum Cooperi, n. s. Small, with 30-40 sharp narrow rin^'j. 



Family Tiirritellidce. 



324. Turritella Cooperi, n. s. Extremely slender, with many narrow whirls, c. Ol', 

 02.). TiD-rilella Jewettii, n. o. Like sanguinea, with very faint sculptore. 



320. Mesalia lacteola, P n. s. May be a local var. of the circumpolar lactea, witli 



altered sculpture : distinct, teste Cuming. 

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



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



Shoal-water, Cp. 



Family Cerithiadce. 



328. Cerithidea sacrata, Gi\A..'EL.'E,.= Calif ornica, Nutt.+^Sato, Grid. Variable in 



shape and soidpture : passes into Mazatlanica, Maz. Cat. no. 395. 



329. *Bittium filosum, Gld. E.^.=Bschrichtii, Midd. Strong, broad, grooved. 

 329i. Bittium ?var. esuriens. Like stetTYeA Jilosum, very naiTow, adult scarcely 



sculptured. 



330. Bittium attenuatum, n. s. Lilre plicatum, A. Ad., or drawn-out esuriens, w.ith 



threads instead of grooves. 



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



over strong radiating ribs. 



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



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



333. * Bittium armillatum, n. a. Same aspect : 3 nearly equal rows of knobs. 



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



anterior rib strong. 



Family Litorinidce. 



335. Litorina planaxis, Nutt. Phil.=pa<Mto, Gld. E.E. Outside plain; columella 



scooped. 



336. Litorina Sitchana, Fin.l.=:sukata, G\i.=rudis, Coop. Rounded, flat, with spiral 



ribs. Var. modesta, Phil, (pars) has sculpture faint : subtenebrosa, Midd., is 

 perhaps a degraded var. Kocks between tides. Lord; 8-10 fm. Lyall [?]. 



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

 thiain ur Jiissoa: perhaps they are related to Alaba. The nucleus oi esuriens and 

 attenuatum has not been seen. 



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