MUSEUM OF COMPARATIVE ZOOLOGY. 127 



produced ; base roundly arcuated ; anterior dorsal slope slightly convexly 

 rounded ; posterior slope a little excavated or concave ; lunule and escutcheon 

 indistinct or none ; teeth, anterior 17, posterior 11, ligamentary fossette unusu- 

 ally large, triangular. Lon. 12.5 ; alt. 6.6 ; diam. 4.5 mm. 



Station 21, 287 fms. 



The general form of this species is not unlike that of L. chuva Gray, hut 

 the rostrum is not so curved or differentiated from the remainder of the shell, 

 and it is not sculptured. I have sought in vain for any figure sufficiently 

 similar in outline to form the basis of a critical comparison. 



Leda intermedia Sars. 



Portlandia intermedia M. Sars ; G. 0. Sars, Moll. Keg. Arct. Norv., p. 38, Tab. 4, 



fig. 9, 1878. 



Station 2, 805 fms. 



This is identified from Sars' figure, above cited. The North Pacific species, 

 mentioned by Jeffreys (P. Z. S., 1879, p. 578), seems to me to differ from it 

 but slightly, if at all. 



Yoldia solenoides n. s. 



Shell thin, elongate-oval, gaping at both ends ; smooth, or marked by a 

 few shallow concentric grooves or flattened ridges about the middle toward the 

 basal part, elsewhere obsolete or absent ; shell whitish, rather pearly ; epider- 

 mis iridescent, thin, dehiscent ; basal and dorsal margins nearly parallel ; beaks 

 very inconspicuous ; lunule and escutcheon extremely narrow, marked by a 

 narrow elevated thread and a groove on each side of the slightly pouting mar- 

 gin ; anterior and posterior ends nearly equal, similar, bluntly rounded ; ante- 

 rior teeth about 18, posterior 22 ; ligamentary fossette large ; lon. 12.5 ; alt. 

 6.0 ; diam. 3.5. Beaks situated 6.5 mm. from the anterior end. 



Station 49, 118 fms. 



This shell looks like a Solenetta ; but the ligament is distinct, and it is per- 

 fectly internal. 



Yoldia liorhina n. s. 



Shell thin, moderately large for the genus, light greenish waxen, clouded 

 with a smoky tinge in some specimens on the convexity of the valves ; inside 

 shining, not pearly; outside polished, brilliant, moderately inflated; beaks 

 nearest the anterior end of the shell, little prominent ; sculpture consisting of 

 rather numerous (about five to a millimeter) concentric grooves, with much 

 wider interspaces, more crowded and fainter toward the beaks, extending from 

 the anterior dorsal margin parallel with the lines of growth to the (lather 

 faint) rostral flexure at the posterior part of the shell, where they rather 

 abruptly cease, and the remainder is extremely smooth and polished : lunule 

 and escutcheon very narrow, bounded externally by grooves, inside <>( which is 



