D. t. parvâ, turrito-conicâ, cerinâ, politâ, nitente; anfr. nucl. ii. naticoideis, vertice mamillato, apice indistincto; norm. v., omnino planatis, suturis indistinctis; peripheriâ acute angulatâ, vix carinatâ; basi omnino planatâ; aperturâ subquadratâ; peritremati continuo; labro postice paullum contracto; labio appresso; columellâ antice angulatâ, vix sinuatâ. Long. 0·15, long. spir. 0·09, lat. 0·07, div. 29°. _Hab._ Catalina Is. 8-10 fm.; on beach to Monterey. _Cooper._ _Diala marmorea_, Cpr. n. s. D. t. solidâ, exacte conicâ, læviâ, nitente; subdiaphane pallidâ, rufo maculatâ; anfr. nucl. rotundatis, planorbeis, sub-oblique sitis, apice celato; norm. vi. planatis, suturis indistinctis; basi planatâ, sub-angulatâ; aperturâ ovali, peritremati continuo, haud varicoso. Long. 0·17, long. spir. 0·11, lat. 0·08, div. 31°. _Hab._ Monterey, S. Pedro; _Cooper_. Lower California, off Haliotis. _Rowell._ The description is written from a single perfect specimen in Mr. Rowell’s collection, and some fragments from the shell-washings of Dr. Cooper’s. Genus STYLIFERINA, A. Adams. _Styliferina turrita_, Cpr. n. s. St. t. minimâ, albidâ, solidiore, lævi, turritâ; anfr. nud. iii. subnaticoideis, apice mamillato; norm. v. planatis, angustis, suturis parum impressis; basi subito rotundatâ, haud umbilicatâ; aperturâ subrotundatâ; labro postice parum contracto. Long. 0·06, long. spir. 0·04, lat. 0·02, div. 20°. _Hab._ S. Pedro. _Cooper._ A single specimen of this tiny shell was found in the shell-washings of Dr. Palmer’s consignment. The mouth is unfortunately choked up with a grain of coarse sand which I have not been able to extract. Genus? JEFFREYSIA, Alder. _? Jeffreysia translucens_, Cpr. n. s. ? J. t. “_Barleeiæ subtenui_” simili, sed tenuiore, tumidiore; corneâ, pallide fulvâ, lævi, nitente, satis diaphanâ; anfr. nucl. normalibus, apice submamillato; norm. iv. subconvexis, suturis distinctis; basi rotundatâ, haud umbilicatâ; aperturâ ovatâ, peritremati vix continuo; labro acuto; labio appresso, regione umbilicari parum calloso. Long. 0·08, long. spir. 0·045, lat. 0·06, div. 55°. _Hab._ S. Diego; in shell-washings. _Cooper._ Only one specimen having been seen, without animal or even operculum, the genus is doubtful. In its slight labial deposit it resembles _“Litiopa” dubiosa_, C. B. Adams. Genus CYTHNA, A. Adams. _Cythna albida_, Cpr. n. s. C. t. minutâ, albidâ, lævi, diaphanâ, latâ; anfr. nucl. normalibus, vertice mamillato; norm. iii. tumidis, rotundatis, rapide augentibus, suturis valde impressis; basi rotundatâ, valde umbilicatâ; umbilico subangulato; aperturâ subrotundatâ; peritremati continuo, acuto, t. adultâ nonnunquam à pariete separato. Long. 0·03, long. spir. 0·015, lat. 0·025, div. 80°.