374 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
The ligament reaches only the distal part of the chondrophore, which is occu- 
pied by the resilium. 
Leda (Jupiteria) pontonia Datt. 
Leda pontonia Dall, Proc. U.S. Nat. Mus., 1889, 12, p. 267, pl. 13, figs. 5, 5b. 
List oF STATIONS. 
Station. Locality. Fathoms. Bottom. Temperature. 
2808 Off Galapagos Ids. 634 coral sand 39°.9 F. (types). 
3360 Gulf of Panama. 1672 sand 36°.4 
8393 Fela sf 1020 green mud 86°.8 
2923 Off San Diego, Cal. 822 & f 89°0.2 
Leda (Jupiteria) excavata Hinps. 
Nucula excavata Hinds, P. Z. S. London, 1848, p. 100; Zool. Voy. Sulphur, 1844, 
Moll., p. 64, pl. 18, fig. 17. 
Panama, in 30 fathoms, mud; Hinds. U. 8. S. ‘ Albatross,”’ station 2794, in 
62 fathoms, sand, bottom temperature 59°.5 F. U.S. N. Mus. 122,763. 
By the emphasis on the posterior carinae visible in this species it begins to ap- 
proach Lembulus. 
Leda (Jupiteria) elenensis Sowrersy. 
Nucula elenensis Sowerby, P. Z. S. London, 1882, p. 198; Hanley, Thes. Conch., 3, 
Mon. Nuculacea, p. 121, pl. 228, fig. 71. 
U.S. S. “ Albatross,” station 2805, in 52 fathoms, mud, Panama Bay. 
This species approaches Z. acuta Conrad, but is less attenuated. According to 
Hanley the surface sculpture is subject to much variation. 
Leda (Jupiteria) acrita Dat, n. sp. 
Shell small, white or translucent, with a very pale straw-colored periostracum, 
subequilateral, swollen, acutely rostrate behind; beaks prominent, adjacent; an- 
terior dorsal margin gently arcuate; posterior slope straight, the opposed margins 
of the valves slightly pouting in the middle of a longitudinally striate, depressed 
escutcheon, bounded by two well-marked but not acute radial ridges; these ter- 
minate at the slightly gaping posterior end; a shallow radial sulcus, sometimes 
accompanied by a faint ray, extends from the beaks to the anterior basal margin, 
with variable strength ; middle of the valves prominent, with a variably strong 
series of short ripples from the beaks to the margin, these ripples absent or obso- 
