P. t. “_P. galeatæ_,” fere exacte simulante; sed laminâ internâ solidâ, planatâ, haud antice sinuatâ, haud suffultâ. Long. 0·30, lat. 0·21, alt. 0·24, div. 70°. _Hab._ Catalina Island, not rare, 40 to 20 fms., _Cooper_, alive. Outside like _P. noachina_; but with the lamina like _P. cucullata_, without eye-holes. The latter species is extremely variable in sculpture, but never so fine as this; and the shape is less conical. Genus GIBBULA, Leach. _Gibbula optabilis_, Cpr. n. s. G. t. parvâ, pulcherrimâ, subconicâ; lurida, fusco-purpureo maculatâ; anfr. v. subquadratis, suturis distinctis; carinis principalibus in spirâ ii., aliâ intercalante; carinâ fortiori peripheriali, et lirulis circ. vi. basalibus, regulariter colore punctatis; lirâ posticâ subobsolete suturam attingente; aliis minoribus intercalantibus; interstitiis ubique tenerrime et creberrime decussatis; basi subtumente, ad carinam peripherialem fere rectangulato; aperturâ subquadratâ, columellâ parum arcuata; umbilico magno, infundibuliformi, angulato; liris ii. intus spiraliter ascendentibus. Long. 0·19, long. spir. 0·10, lat. 0·19, div. 80°. _Hab._ San Pedro, _Palmer_, one specimen. Genus CALLIOSTOMA, Swainson. The names _Calliostoma_ and _Ziziphinus_ having been published in the same year, I have no hesitation in preferring the generic to the specific. _Calliostoma supragranosum_, Cpr. n. s. C. t. parvâ; anfr. v. tumentibus; liris acutis cincta, quarum mediæ læves, posticæ granosæ, basales ix. minores. _Hab._ San Diego; _Cooper_. The single specimen sent differs as above from the young of the next species. _Calliostoma gemmulatum_, Cpr. Br. Assoc. Rep. 1863, pp. 612, 653. Syn. _C. formosum_, Cpr. Proc. Cal. Ac. 1864, 155: non Forbes. While the sheets of the Report were passing through the press, it was found that the name had been preoccupied by Forbes. As it happened the Californian sheet was being printed simultaneously, and there was no time to make the alteration. Genus ETHALIA, Adams. _Ethalia supravallata_, Cpr. n. s. E. t. parvâ, albidâ, nitente, subdiaphanâ, planatâ; anfr. nucl. ii. et dimidio, lævis, diaphanis; norm. uno et dimidio, rotundatis; postice carinâ valde extante, et fossâ concavâ contiguâ suturam tenus, supra spiram vix planatam ascendente; in medio basis rotundatæ carinâ alterâ plus minusve extante; inter eas, circa peripheriam, lirulis radiantibus minimis, haud expressis, sub lente vix conspicuis; regione umbilicari parum concavo; aperturâ circulari; labro à carinis angulato; columellâ, valde callosâ, porrecta; callositate pyriformi regionem umbilicarem circumambiente. Long. 0·03, long, spir. 0. (?) lat. 0·45, div. 180°. _Hab._ San Diego, _Cooper_, shell-washings.