R. t. tenui, satis turritâ, rufocinereâ, marginibus spiræ parum excurvatis; anfr. nucl. iii. normalibus lævibus, vertice parum mamillato; norm. iii. subrotundatis, suturis valde impressis; liris radiantibus circ. xviii. acutis, distantibus, ad peripheriam evanidis; lirulis acutis spiralibus distantibus circ. xv., quarum vi. in spirâ monstrantur, liris radiantibus et interstitiis latis, undatis, eleganter superantibus, haud nodulosis; basi rotundatâ, haud umbilicatâ; aperturâ ovatâ, peritremati continuo. Long. 0·09, long. spir. 0·05, lat. 0·05, div. 35°. _Hab._ S. Diego; 1 sp. and fragment in shell-washings. _Cooper_. Genus FENELLA, H. & A. Adams. _Fenella pupoidea_, Cpr. n. s. State Collection, No. 389. F. t. _Truncatellæformi_, sed apice haud decollato; colore maxime variante; seu unicolori, albido, cinereo, viridescente, rufofusco, seu splendide rubro; seu varie fusco maculato; anfr. nucl. iii. lævibus, globosis, vertice mamillato; norm. v. rotundatis, fere æqualibus, plus minusve solutis, suturis subimpressis; totâ superficie tenue spiraliter striatâ; striis in spirâ majoribus, circ. viii. distantibus, minoribus creberrimis intercalantibus; circa basim rotundatam circ. x. majoribus, contiguis, minoribus paucis; aperturâ circulari, peritremati continuo, solido, ad suturam parum callosam appresso; umbilico nullo. Long. 0·23, long. spir. 0·16, lat. 0·09, div. 12°. _Hab._ Monterey, 20 fm. 45, dead. _Cooper._ Genus AMPHITHALAMUS,[20] Cpr. Testa _Rissoidea_; nucleo magno; apertura labio producto, labro subpostice juncto, subito in adultâ contracta. _Type._ _Amphithalamus inclusus_, Cpr. Br. Assoc. Rep. 1863, p. 656; Ann. Nat. Hist. Jan. 1865. _Hab._ Santa Barbara, _Jewett_; S. Diego, in shell-washings. _Cooper._ _? Amphithalamus lacunatus_, Cpr. n. s. ? A. t. adolescente “_A. incluso_” simili; nucleo similiter minutissime et confertissime spiraliter et radiatim striulato; sed majore, latiore, anfr. subplanatis; basi late lacunatâ, haud carinatâ; adultâ ?.. Long. 0·06, long. spir. 0·03, lat. 0·03, div. 50°. _Hab._ San Pedro. _Cooper._ Two dead specimens in the shell-washings of Dr. Palmer’s consignment to the Smithsonian Institute might have been passed over as the young of _Barleeia subtenuis_, but for the possession of exactly the same remarkable nucleus as _A. inclusus_. It is presumed, therefore, that they are congeneric; if so, the adult has not been seen. Genus DIALA, H. & A. Adams. _Diala acuta_, Cpr. n. s. State Collection, No. 390.