NO. 1139. DEEP-WATER MOLLrSCAVERRILL AXD BUSH. 855 



LEDA PERNULA (Miiller). 

 (Plate LXXXII. tig. 2.) 



Leda pernula G. O. SARS, Mollusra Ueg. Arctic.-!- Norvi-gin-. p. 35, pi. .">, ligs. 1 

 ti-<l, 1878. JEFFREYS, Pror. Zool. Soc.. London, p. 571, .June, 1879. YKK- 

 RILL, Proc. U.S. Nat. Mus., Ill, p. 401, 1881; Trans. Conn. Ac-ad., V, p. 572, 

 1882; not VI, p. 280, pi. xxx, figs. 14, Ua, 1884. Not PALL, Bull. U. S. Nat. 

 Mus., No. 37, pi. XLY, figs. 14, 14o, 1889. 



Found at a number of stations between X. Lit. 46 23', W. long-. 52 45', 

 and N. lat. 37 8', W. long. 74 33', in 25 to 471 fathoms, 1872-1885. 



LEDA CAUDATA (Donovan). 

 (Plat.- I. XXXII, fig. 1.) 



Area caudata DONOVAN, British Shells, pi. LXXVIII; Cheim ed., p. 50, pi. xvn, 



figs. 8-12. 

 Leda caudata LOVEN, Ind. Moll, grand., p. 34. GOULD, Rep. on Invert, of Mass., 



Biuney's ed., p. 165, fig. 471, 1870. TRY ON, Ainer. Mar. Conch., p. 182, pi. 



xxxvin, figs. 494, 495, 1873. 

 Lcda pernula VERRILL, Trans. Conn. Acad., V, p. 572, 1882, in part; VI, p. 280, 



pi. xxx, figs. 14, 14, 1884. PALL, Bull. U. S. Nat. Mus., No. 37, pi. XLV, 



figs. 14, Ua, 1889. (?) BUSH, Bull. Mus. Comp. Zool.. XXIII, p. 234, 1893. 

 Leda caudata VERHILL and BUSH, Amer. Journ. Sci., Ill, p. 54, fig. 19, January, 



1897. 



This deeper- water form, previously identified as Leda pernula, was 

 found at a very few stations between N. lat. 42 57', W. long. 69 50'. and 

 K. lat. 37 16' 30", W. long. 74 20' 36", in 102 to 641 fathoms, 1874-1885. 



LEDELLA Verrill and Bush, 1897. 



Junonia SEGUENZA, Nuculidi tc-rziarie merid. d' Ital., R. Acad. Lincei, p. 1175, 



1877 (not of HUBNER). 

 Ledella VERRILL and BUSH, Amer. Journ. Sci., Ill, pp. 54, 62, January, 1897. 



Type. Ledella messanensis (Seguenza). 



This group includes a large number of small species, both living and 

 fossil, in which the shell is rather short, usually ovate or swollen, with a 

 small, acute or subacute unicariate rostrum, situated medially or sub- 

 uiedially, and defined below by an emargination or undulation in the 

 postero-veutral margin. The postero-dorsal margin is convex. The 

 escutcheon or ligamental area is very distinctly defined by the carina, 

 but is not sunken. The choudrophore is usually small but distinct. The 

 si phou tubes are separate, at least in some species. It includes numerous 

 minute tertiary species referred by Segueuza to the section of Lejda 

 named by him Junonia, and also a considerable number of recent deep- 

 water species generally described by authors under Leda. As the 

 name Junonia was preoccupied, the group, which seemed to be of generic 

 value, required a new name. 



The following species appear to belong here: 



L. seminula (Segueuza), L. nicotnr (Seguenza), L. peraffinls (Se- 



