2 M i'iiM>i-i.i:rRU8. 



spongy. Girdle downy, having small, tufted pores. Type, H. set- 

 ulosiun ( 'j.r. 



A A. Valves partly covered, the expose< small and sepa- 



rated. 



\\\( K< H'LA X Adams & Angas, 1804. 



Insertion plates smooth and thin, well developed in all the valves, 

 ml plates and sinus obsolete. Girdle thin, most minutely gran- 

 ular, not jMriferous. Type, M. proyiAd. & Ang. 



Gem.- I. LEPIDOPLEURUS Riaso, 1826. 



pleurus Risso, Hist. Nat. 1'Kur. M.'rid., iv, p. 267, 1826, 



in : t species /,. c,ij*t>tnns Poll). SARS., Moll. Reg. Arct. 



., 1*7*, }. 1 in. Nut L'-ftidoplenrus of H. & A. Adams, Car- 



: 'all. ft i/.Lrptorhiton GRAY, Proc. Zool. Soc. Lond. 1847, 



j. 1 H I 1 .. M.. p. 182, 1857. CARPKM I:K, J/& p. 1, 



- ; . Mus. 1878, p. 3\.Leptochiton, in part, of 



H. A A. A i. A MS, Gen. Rec. Moll, i, p. 473, and of CHUM , 



Manuel, i, p. 381. 



In / itioii plates are completely absent; the 



girdle is narrow, with minute striated or smooth scales, and some 

 _rer scales at the edge. 

 The present genus has hitherto been known as Leptochiton, but 



:vji-i-tioM of that name seems to be inevitable as will be seen 



DO the following: 



// '. of the name Lfj'irli>/>-urii.<. The first publication of 



Lepi- l in Kisso's Histoire Naturelle des principales pro- 



! Mi'ridiojiale, vol. iv, p. 267, 182G, where ii is 



NJ as of Leach's ww. It is character! zed as having the triangular 

 lateral areas elevated and the girdle covered with small scales, and 

 in it are includ<-d .711) L. cayetanns Poli, (712) L. coral/inn* n. sp. 

 and (713) L. sul&itus n. sp. Of these, the first species belongs to 

 the v ' . Mib.-e.juently named I,e]ttocliiton, and the 



two latter belong to the genus Chiton as restricted to Lin nuns' 

 type. It is there!'"!.' evid.-nt that if u>.-d at all. the name Lepido- 

 plcn ;.rojM-rly be ii>,-d foi | ,,,,lv. It is greatly to 



be regretted that it was not so used by < iray, as much subsequent 

 confusion would have been avoided. The rej.ublication of the 



