236 AMERICAN JOURNAL 



Class GASTEROPODA. 



Order DOCOGLOSSA, Dall ex Troscliel. 



Suborder ABRANCHIATA (Gill) Dall. 



Animal destitute of eyes or branchiag, furnished with a rhachi- 

 dian tooth and uncini, but without lateral teeth upon the radula. 



Family LEPETID^.* 



Shell with apex anteriorly directed, patelliform ; muzzle pro- 

 longed below in two tentacular appendages; teeth, •myoyi- 



Genus LEPETA, Dall ex Gray. 



Subgenus Lepeta, Dall. 



Rhachidian tooth tricuspid, concave in front. Central cusp 

 much the largest, simple ; lateral cusps small, cmarginate. Base 

 very broad. Uncini with simple cusps. 



Subgenus Cryptobranchia, Dall ex Midd. 



Rhachidian tooth with three short cusps, equal and parallel 

 before and behind, not pointed. Base more or less ornate be- 

 hind, moderately broad. Uncini with simple cusps. 



Subgenus PiLiDiUM,t Forbes. 



Rhachidian tooth tricuspid, convex before, central cusp much 

 the largest, lateral cusps simply pointed ; base very narrow. 

 Uncini with cusps obliquely twisted. 



Suborder FROTEOBRANCHIATA, Dall. 



Animal branchiferous, oculiferous. Rhachidian tooth rarely 

 present. Lateral teeth invai-iably present ; three in number. 



* For synonymy, &c., see "Materials for a Monograph of the Family 

 Lepetidse," by W. H. Dall, Am. Journ. Conch, v, pp. 140- — 150. 



f Although Forbes and Hanley were acquainted with the Lepeta cceca 

 of IVliiller, it would appear that they erected the Patella fulva into a dis- 

 tinct genus upon the erroneous supposition that the apex of Lepeta was 

 directed posteriorly. The genus Lepeta is Atlantic, and Cryptobranchia 

 is Pacific, in its distribution. I have seen no true Lepeta cceca from the 

 Pacific, though it has been frequently reported from Japan and else- 

 where. All the Pacific specimens sent by Dr. Carpenter under that 

 name, and those in the Smithsonian collection dredged by Mr. A. Adams 

 in Japan, and so denominated, upon inspection and actual comparison 

 are undoubtedly diiTerent, and probably couspecific with Ciyplobranchia 

 concentrica, Midd. 



