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.