856 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL.XX. 



guenza), L. redidorsata (Seguenza), L. confusa (Seguenza), fossil; L. 

 solidula (Smith) and L. semen (Smith), from off Brazil; L. conjinis 

 (Smith), off the Azores; L. inopinata (Smith), L. prolata (Smith), and 

 L. ultima (Smith), from the Pacific; L. messanensis (Seguenza), from 

 off the Barbados, northward; L. messanensis (Seguenza) var. sublems 

 Verrill and Bush, oft' Delaware Bay, northward; and L. parva Verrill 

 and Bush, off Marthas Vineyard. 



LEDELLA MESSANENSIS (Seguenza). 

 (Plate LXXXI, fig. 9.) 



Leda acuminata JEFFREYS, Aim. Mag. Nat. Hist., p. 69, July, 1870 (not VON 

 BUCK). SEGUENZA, Nuculidi terziarie merid. d' ItaL, R. Acad. Liucei, 1877, 

 p. 1175, pi. in, figs. 15, 15a, 15e. 



Leda messanensis JEEFREYS, Proc. Zool. Soc. London, p. 576, June, 1879. SMITH, 

 E. A., Report Voy. Challenger, Zool. Lamellibranchiata, XIII, p. 237, 1885. 

 DALL, Bull. Mus. Comp. Zool., XII, p. 249, 1886; Bull. U. S. Nat. Mus., No. 

 37, p. 44, 1889. 



The shell which is here regarded as the true messanensis is small, 

 swollen, ovate, nearly equilateral, with a distinct, short, oblique rostrum 

 bent downward at the tip and separated from the body of the shell by 

 a distinct depression and marginal indentation. The shell is thick and 

 solid for so small a species; its surface is covered with fine, regular, 

 raised, thin, concentric lines separated by wider concave grooves. The 

 hinge-margin is thick, strong, with about seven or eight, mostly strong, 

 nearly erect, and not crowded, teeth in each series. The choudrophore 

 is relatively large, triangular, and projects on the inner margin. The 

 epidermis is pale yellow. According to Jeffreys the siphon tubes are 

 long and separate. 



Length, about 2.G mm.; height, about 2 mm. 



A few specimens, at three stations between N. lat. 38 29', W. long. 

 73 9', and N". lat. 37, W. long. 71 54', in 965 to 2,620 fathoms, 1884-85. 

 South to the Barbados, in 32 to 2,033 fathoms. Dall. 



i 



LEDELLA MESSANENSIS (Seguenza) variety SUBLEVIS, new. 



(Plate LXXXI, fig. 7.) 



Toldia messanensis, variety A T ERRILL, Trans. Conn. Acad., VI, pp. 227, 280, 1884; 



Expl. Albatross, Report U. S. Com. Fish and Fisheries for 1883, p. 576, 1885. 

 Ledella messanensis, variety VERRILL and BUSH, Amer. Journ. Sci., Ill, p. 60, 



fig. 13, January, 1897. 



This variety differs from the form above described, principally in 

 having the concentric sculpture wholly or partially obsolete and in its 

 somewhat more elongated form. It has nine or ten teeth in each 

 series, due perhaps to the larger size of the specimen. 



Comparatively few specimens, at thirteen stations, between K. lat. 

 420 47/ r w. long, 61 4', and N. lat. 38 20', W. long. 70 8' 30", in 1,188 

 to 2,033 fathoms, 1883-1886. 



