L. t. parvâ, primum subdiscoideâ, postea variante, albido-cinereâ; anfr. nucl. lævibus, planatis, apice depresso; anfr. norm. ii. et dimidio, convexis; clathris validis distantibus circ. xv. radiantibus, et vii. spiralibus, subæquantibus, conspicue fenestratâ; aperturâ circulari, sæpius plus minusve declivi, parieti vix attingente; umbilico maximo, anfractus monstrante; labio, regione umbilicari, sinuato. Long. 0.09, long. spir. 0.04, lat. 0.12, div. 170°. _Hab._ Catalina Island; beach to 40 fms. 20, dead. This strongly sculptured species varies greatly (in the two specimens sent to the Smithsonian Institution), in the declivity of the mouth and consequent size of the umbilicus, where the labium is, as it were, scooped out. _Liotia acuticostata_ Carp. n. sp. State Collection, Species 519 a. L. t. parvâ, subglobosâ, albâ; anfr. nucl. ii. lævibus, apice satis extante; anfr. normalibus iii., carinis in spirâ maxime extantibus ii., anfr. ult. vi.; suturis subrectangulatis; aperturâ circulari; labro extus parum contracto; labio conspicuo; umbilico haud magno. Long. 0.12, long. spir. 0.06, lat. 0.10, div. 95°. _Hab._ Catalina Island, 10-20 fms. 4, alive; Monterey, 4, dead, dredged? This pretty little Cyclostomoid species is easily recognized by the sharp revolving keels, and absence of radiating sculpture. AMYCLA H. & A. Adams, 1858. _Amycla undata_ Carp. n. sp. State Collection, Species 1067. A. t. parvâ rufo-fuscâ, turritâ, epidermide tenui indutâ; marginibus spiræ subrectis; anfr. nucleosis iv. lævibus, tumidis, apice mamillato; anfr. normalibus v. valde tumidis, suturis impressis; costis radiantibus ix. valde tumidis, latis, antice et postice obsoletis; interstitiis undatis; liris spiralibus acutioribus, distantibus, costas superantibus, secundum interstitia eleganter undulatis, quarum vi.—viii. in spirâ monstrantur; aperturâ ovali, in canalem brevem rectam productâ, intus haud liratâ; labro acuto, labio acuto extanti ad suturam juncto; columellâ planatâ: operculo nassoideo. ? Long. 0.44, long. spir. 0.20, lat. 0.20, div. 45°. _Hab._ Catalina Island, not rare, 30-40 fm. 10, some alive. The nuclear whirls in this shell resemble a minute _Paludina_. The only operculum in the specimens sent was broken in extraction, but appeared to be Nassoid. The sculpture consists of elongate knobs swelling in the middle; with spiral lines hanging as it were from pier to pier, as in a suspension bridge. The aperture is somewhat Columbelloid, the inner and outer lips joining at the suture; but neither are lirate within, although they have that appearance from the outside sculpture showing through.