1879.] ' lightning' and 'porcupine' expeditions. 579 



C. Espichel, 22. This form appears to be the variety salicensis of 

 Seguenza. Another variety, which I would call semistriata, is 

 smoother, thinner, more glossy, and is partially striated either at 

 the anterior end only or towards the front margin. It occurred in 

 the ' Lightning ' Expedition, Station 6, and in the ' Porcupine ' 

 Atlantic Expedition of 1870 at the following Stations, 2, 3, 6, 8, 9, 

 17, 24, 26-28a, 30-54. Young specimens of both varieties are 

 nearly oval. 



Distribution. 'Valorous' Exp. (var. salicensis), 'Josephine' Exp. 

 (off the Azores ; var. semistriata) ; 550-1750 fms. 



Fossil. Pliocene. Vienna Basin, Italy from Leghorn to Messina. 

 Var. semistriata, Messina. 



B. Rounded at both ends. 



1/ 15. Leda sericea, Jeffreys. (Plate XLVI. fig. 1.) 



L. sericea, Jeffr. in Ann. and Mag. N. H. Nov. 1876, p. 432. 

 ' Porcupine ' Exp. 1869: St. 19, 21, 30. 1870: Atl. 1 (var. 

 ovata, longer in proportion to the breadth, but having the charac- 

 teristic sculpture of the species), 16, 17, 17«. 

 Distribution. ' Valorous ' Exp. ; 1450 fms. 



t, 16. Leda jeffreysi, Hidalgo. (Plate XLVI. fig. 2.) 



L. lata, Jeffr. in Ann. and Mag. N. H. Nov. 1876, p. 431. 



' Porcupine' Exp. 1869: St. 9, 20, 30, 31. 1870: Atl. 16, 17, 

 17a. 



Distribution. 'Valorous' Exp., 'Challenger' Exp. (between the 

 Azores and Bermuda) ; 690-1785 fms. 



Dr. Hidalgo, in his work above mentioned, has pointed out that 

 the specific name lata (which I gave this shell) had been preoccupied 

 by Mr. Hinds in the * Zoology of the Voyage of H.M.S. Sulphur ' 

 (1845) for a New-Guinea species, and that, although named there 

 Nucula lata, it belonged to the genus Leda. He accordingly pro- 

 posed to cancel the name lata and call the present species by my 

 own name, a compliment for which I am grateful. 



1 7. Leda sub^ouilatera ', Jeffreys. (Plate XLVI. fig. 3.) 



Shell transversely oblong-oval, nearly equilateral, somewhat 

 depressed, rather thin, glossy, semitransparent : sculpture none 

 except a few irregular periodical lines of growth : colour whitish : 

 epidermis yellowish-white : margins obtuse-angled and pinched up 

 at the back, equally rounded at each end, slightly produced or ex- 

 tended on the anterior side, gently curved in front : beaks almost 

 central, prominent, rather gibbous, and incurved : lunule wanting, in 

 consequence of the pouting and sharp margin at the back: cartilage 

 and pit very minute, the latter sunken : hinge-line obtuse-angled : 

 hinge-plate rather narrow, but strong : teeth small, erect and comb- 

 like, 8 on each side, besides 4 or 5 minute tubercles near the beak ; 



1 Nearly equilateral. 



37* 



