C. t. tenuissimâ, subdiaphanâ, latiore; forma “_Scintilæ Cummingii_” simulante; extus argenteo-iridescente, striulis incrementi exillimis interdum uudatâ; parte posticâ paullum majore rotundatâ; intus, valvâ dextrâ dent. ii. laminatis, arcuatim divergentibus, extantibus, quorum anticus major, ventraliter sulcatus; v. sinistr. iii., quorum ant. et post. laminati, arcuati, centralis triangularis, bifidus; fossâ cartilaginali parvâ, semi-internâ, sub umbones angustiores, satis prominentes, sitâ; laminâ ligamentali nullâ, nymphis longioribus; sinu pallii oblongo, lato; lineâ pallii anticâ minus declivi. Long. 0·60, lat. 0·48, alt. 0·32. _Hab._ San Diego; San Pedro, 2 dredged in 8-20 fms. _Cooper_. Genus SEMELE, Schum. _Semele incungrua_, Cpr. n. s. State Collection, No. 1061. S. t. formâ et indole “S. pulchræ” simili, sed sculpturâ diversâ; transversâ, tenuii, subplanatâ, umbonibus prominentibus; pallide carneâ, radiis intensioribus ornatâ; totâ superficie minute et creberrime radiatim striulatâ; marginibus dorsalibus postico rectiore, antico parum incurvato; reliquis regulariter excurvatis, parte anticâ diagonaliter valde productâ; v. sinistr. liris crebris subacutis concentricis, antice sæpe irregulariter interruptis, postice circiter quaternis solum conspicuis, extantibus; v. dextr. liris pancioribus, acutis, antice vix interruptis, postice alternantibus, extantibus: intus; dent, card. parvis, fossâ cartilaginali angustâ elongatâ; dent. lat., v. dextrâ, elongatis, regione cardinali purpureo tinctis; cicatr. adduct. subrotundatis; sinu pallii maximo, ovali, ascendente, per quintas inter sex totius interstitii partes porrecto; colore secundum paginam externam tinctà et radiatà. Long. 0·58, lat. 0·40, alt. 0·16. _Hab._ Santa Barbara, 16 fm. 1 valve; Catalina Island, 40-60 fm., not uncommon; _Cooper_. Genus? VENUS, _Ln._ Subgenus PSEPHIS, Cpr. 1864. _Psephis salmonea_, Cpr. n. s. State Collection, No. 1068. Ps. t. Parvâ, subinflatâ, subæquilaterali, subtrigonâ; colore salmoneo; extus nitidâ minutissime et creberrime concentrice striatâ; margine ventrali excurvato; dorsalibus antico et postico subrectis: intus, dent. card. iii.-iii., quorum utrãque valvâ anticus porrectus, quasi lateralis, centrales parvi; v. dextr. dente postico in marginem sulcatum decurrente; cicatr. adduct. satis conspicuis, subrotundatis; lineâ pallii satis internâ, vix obsolete sinuatâ. Long. 0·12, lat. 0·11, alt. 0·06. _Hab._ Catalina Island, 30-40 fm., rare.; _Cooper_. Placed under Psephis by analogy; whether the animal be ovoviviparous has not yet been ascertained. Genus ASTARTE, J. Sby. _Astarte fluctuata_, Cpr. n. s. State Collection, No. 1060.