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 Dall. 

 Leda pontonia Dall, Proc. U. S. Nat. Mus., 1889, 12, p. 257, pi. 13, flge. 6, 56. 



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 



3393 " " " 1020 green mud 36°.8 



2923 Off San Diego, Cal. 822 " " 39°0.2 



Leda (Jupiteria) excavata Hinds. 



Nucula excavata Hinds, P. Z. S. London, 1843, p. 100 ; Zool. Voy. Sulphur, 1844, 

 Moll., p. 64, pi. 18, fig. 17. 



Panama, in 30 fathoms, mud ; Hinds. U. S. S. " Albatross, " station 2794, in 

 62 fathoms, sand, bottom temperature 59°.5 F. U. S. N. Mns. 122,763. 



By the emphasis on the posterior carinae visible in this species it begins to ap- 

 proach Lembulus. 



Leda (Jupiteria) elenensis Sowerby. 



Nucula elenensis Sowerby, P. Z. S. London, 1832, p. 108 ; Hanley, Thes. Conch., 3, 

 Mon. Nuculacea, p. 121, pi. 228, fig. 71. 



U. S. S. " Albatross," station 2805, in 52 fathoms, mud, Panama Bay. 

 Tliis species approaches L- acuta Courad, but is less attenuated. According to 

 Ilanley the surface sculpture is subject to much variation. 



Leda (Jupiteria) acrita Dali., n. sp. 



Shell small, white or translucent, with a very pale straw-colored periosfracum, 

 subequilatcral, swollen, acutely rostrate behind; beaks prominent, adjacent; an- 

 terior dorsal margin gently arcuate; posterior slope straight, the opposed margins 

 of the valves shglitly 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 

 scries of short ripples from the beaks to the margin, these ripples absent or obso- 



