Cœcum Cooperi, Cpr. n. s. State Collection, No. 667a.
C. (Anellum) t. parvâ, satis tereti, albâ; annulis crebris acutioribus, angustis, circ. xxxiv.-xxxviii., interstitiis subconcavis; septo subungulato; apice obtuso, haud elevato, margine laterali recto; aperturâ declivi, parum contracto et postice expanso; operculo?
Long. 0·09, lat. 0·025.
Hab. San Diego and Catalina Island, 8-10 fms., 18, Cooper.
Known from similar Mazatlan species by the very numerous but separated and somewhat sharp ribs.
Genus Turritella, Lamarck.
Turritella Cooperi, Cpr. n. s. State Collection, No. 564.
T. t. valde tereti, tenuiore, cinereâ, rufofusco tinctâ; anf. plurimis, angustis, subplanatis, suturis distinctis; liris ii. et striulis crebris spiraliter ornatâ; basi angulatâ; aperturâ subquadratâ; labro valde sinuato.
Long. 1·80, long. spir. 1·50, lat. 0·45.
Hab. San Pedro, 60; San Diego, 16 dead on beach; Santa Barbara, 4 dead, in 16-20 fms. Cooper.