Typical among the Vitrinelloid _Ethaliæ_ described in Maz. Cat., Nos. 310, 318. Remarkable for the small number of turns in the mature shell as compared with the nucleus. _Ethalia var. invallata_, Cpr. E. t. “_E. supravallatæ_,” aliter exacte simili; sed vallo spirali omnino carente; basi angulatâ, haud carinatâ. _Hab._ San Diego, shell-washings, _Cooper_. These shells would certainly have been regarded as distinct, but for one specimen which began smoothly, yet after a fracture suddenly commenced a (not prominent) keel: an instructive lesson on variations in sculpture. Genus GALERUS, Humphreys. _Galerus contortus_, Cpr. n. s. State Collection, No. 369. G. t. parvâ, tenui, albidâ; vertice nucleoso planato, extante, minimo, anfr. uno et dimidio planorbi-formibus, apice conspicuo; dein conoideâ, elevata, solute spirali, suturis impressis; superficie rudi, laminis incrementi interdum conspicuis; laminâ internâ. Long. 0·26, lat. 0·24, alt. 0·15, div. 80°. _Hab._ Monterey, 20-40 fm.; Santa Barbara, 16-20 fm.; Catalina Island, 30-40 fm.; _Cooper_. The vertex stands out like a tiny Planorbis, and is more minute than in any species I have examined. Genus CÆCUM, Fleming. _Cæcum crebricinctum_, Cpr. n. s. State Collection, No. 388. C. (_Anellum_) t., quoad genus, magnâ, tereti, solidiore, rufofusca, interdum radiis intensioribus longitudinalibus ornatâ; annulis gracillimis, creberrimis, rotundatis, haud elevatis circ. lxxx. cinctâ; interstitiis nullis; sculpturâ longitudinali nullâ; aperturâ acutâ, vix contractâ, vix declivi; septo subungulato, submucronato; margine laterali recto; apice acuto, ad angulum circ. 45°, maxime elevato; operculo vix concavo, lirâ spirali elevatâ. Long. 0·14, lat. 0·04. _Hab._ San Diego, 8-10 fms., 12; Monterey, 20 fms., 20, some alive; Santa Barbara, 20 fms., 3, _Cooper_. Has the aspect, but not the sculpture, of an Elephantulum. _Cœcum Cooperi_, Cpr. n. s. State Collection, No. 667a. C. (_Anellum_) t. parvâ, satis tereti, albâ; annulis crebris acutioribus, angustis, circ. xxxiv.-xxxviii., interstitiis subconcavis; septo subungulato; apice obtuso, haud elevato, margine laterali recto; aperturâ declivi, parum contracto et postice expanso; operculo? Long. 0·09, lat. 0·025. _Hab._ San Diego and Catalina Island, 8-10 fms., 18, _Cooper_. Known from similar Mazatlan species by the very numerous but separated and somewhat sharp ribs. Genus TURRITELLA, Lamarck. _Turritella Cooperi_, Cpr. n. s. State Collection, No. 564. T. t. valde tereti, tenuiore, cinereâ, rufofusco tinctâ; anf. plurimis, angustis, subplanatis, suturis distinctis; liris ii. et striulis crebris spiraliter ornatâ; basi angulatâ; aperturâ subquadratâ; labro valde sinuato. Long. 1·80, long. spir. 1·50, lat. 0·45.