MUSEUM OF COMPARATIVE ZOOLOGY. 249 



Subgenus LEDA Schumacher (s. s.). 

 Leda Carpenteri Dall. 



Leda Carpenteri Dall. Bull. M. C. Z., IX. p. 125, 1881. 

 Plate \1TI.. rig. 11 ; Plate IX. Fig. 3. 



Habitat. Barbados, 100 fms. ; Station 5, 229 fms. ; Station 9, 111 fms., bot- 

 tom temperature 55°.0 F. ; Station 21, 287 fms.; Station 128, 180 fms., off 

 Frederikstadt ; off the Carolina coast, U. S. Fish Commission, 1885. 



Since describing this species I have been able to compare it with specimens 

 dredged by the Fish Commission in some abundance farther north, and with 

 Leda clavata Calcara, a Sicilian fossil which is its nearest relative. L. Carpen- 

 teri differs from clavata in its greater smoothness and in having the hinge-line 

 narrower, the teeth smaller, more delicate, and less numerous, especially the 

 anterior series ; the ligamental pit is much smaller, and the series of teeth 

 are straighter and with much less margin between them and the edge of the 

 dorsal crest. The raised line inside the rostrum is in clavata nearly in the 

 middle of the shell ; in Carpenteri it is invariably nearer the dorsal edge, thus 

 making the dorsal channel distinctly narrower than the ventral one. 



In fresh specimens of L. Carpenteri, especially youngish shells, the pale green 

 epidermis is marked by a beautiful radiating series of arched striae, only visi- 

 ble with a glass except in very marked cases, or near the ventral edges of the 

 valves where the striation is strongest. It is absent in decorticated specimens, 

 and so would appear to be purely a character of the epidermis. 



Leda clavata has been erroneously united with L. cuspidata, which differs 

 both in shape and sculpture. I have not seen any recent specimens of 

 clavata or cuspidata. Some marked as such in the Jeffreys collection were 

 L. Carpenteri. 



Leda messanensis Seguenza. 

 Leda messanensis Seguenza, Dall, Bull. M. C. Z., IX. p. 124, 1881. 



Habitat. Station 19, 310 fms. ; Station 20, 220 fms. ; Barbados, 100 fms.; 

 Sigsbee, off Havana, 450 fms. 



This species, which I have compared with specimens received from the 

 author, varies in sculpture much like the others, being sometimes almost 

 wholly smooth, and at others with well developed concentric sculpture; it also 

 varies remarkably in proportional length, some specimens being rery short 

 and high. In considering these variations, one cannot help surmising that the 

 present number of nominal species of these little shells will eventually require 

 to be diminished. 



