_Hab._ S. Pedro; in shell-washings. _Cooper._ Known from _C. tumens_, Maz. Cat. No. 421, by the non-keeling of the umbilicus. Genus CHRYSALLIDA, Cpr. _Chrysallida pumila_, Cpr. n. s. Chr. t. minutâ, angustâ, albâ; vert. nucl. subito immerso, dimidium truncationis tegente; marginibus spiræ parum excurvatis; anfr. norm. iv. planatis, suturis vix distinctis; clathris radiantibus rectis, validis, planatis, circ. xx., marginibus spiræ utroque latere parallelis, sæpius attingentibus, circa basim elongatam, rotundatam continuis; interstitiis lirulis acutis distantibus, haud extantibus, circ. x. decussatis, quarum iv. v. in spirâ monstrantur; aperturâ ovali, peritremati vix continuo; plicâ parietem tenus acutâ, haud celatâ, declivi. Long. 0·06, long. spir. 0·03, lat. 0·025, div. 12°. _Hab._ S. Pedro. _Cooper._ One specimen and a few fragments were found in the shell-washings of Dr. Palmer’s consignment. Differs from _Chr. ovulum_, in its slender shape and delicate spiral sculpture. _Chrysallida cincta_, Cpr. n. s. Chr. t. satis regulari, albâ, marginibus spiræ vix excurvatis; vert. nucl. parvo, celato, dimidium truncationis vix superante; anfr. norm. iv. parum excurvatis, suturis distinctis; costis spiralibus obtusis circ. x, cinctâ, quarum iv. in spirâ monstrantur; costis iii. posticis radiatim subgranulosis, seriebus circ. xv., marginibus spiræ utrinque parallelis, supra quartam subobsoletis; interstitiis latis, delicatim decussatis; basi satis prolongatâ; columellâ antice valde effusâ; plicâ parvâ, medianâ. Long. 0·11, long. spir. 0·07, lat. 0·05, div. 35°. _Hab._ Santa Barbara group of islands. _Cooper._ The solitary specimen is probably immature. Intermediate between _Chrysallida_ proper and _Mumiola_. Genus CHEMNITZIA, D’Orbigny. _Chemnitzia chocolata_, Cpr. n. s. State Collection, No. 428. Ch. t. “_C. tridentatæ_” magnitudine et indole simili; sed teretiore, dense castaneâ, fasciis pallidioribus sub epidermide adhærente ornatâ; anfr. primis gracillimis; vert. nucl. anfr. iii, helicoideis, valde decliviter sito, marginibus spiræ rectis, angustis, haud superante; anfr. norm. xii. planatis, primis tumidioribus, suturis impressis; costis circ. xxviii. rotundatis, validis, circa basim prolongatam haud subito evanidis, anfr. ult. sæpe obsoletis; interstitiis haud æquantibus, haud undatis, haud sulcatis; totâ superficie sub lente minutissime et creberrime spiraliter striulatâ; aperturâ ovali, columellâ parum contortâ, labro intus tenui, haud dentato. Long. 0·55, long. spir. 0·43, lat. 0·13, div. 17°. _Hab._ S. Pedro, S. Diego, Monterey; rare. _Cooper._ One specimen, in Dr. Palmer’s consignment, is known from _Ch. tridentata_ by the very effuse spire, prolonged base, and crowded ribs without waved sculpture between.