852 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL.XX. 



no valid excuse for applying it to a different group (Leda), that had 

 already received a valid name, as was done by H. and A. Adams. 



That a species belonging to Leda was mentioned by Link does not 

 alter the case, for all the species of Leda, and Toldia then known were 

 referred to Nucula by Lamarck and all other conchologists. 



NUCULA PROXIMA Say, variety OVATA, new. 

 (Plates LXXXI, fig. 6; LXXXVIII, fig. 5.) 



We designate by this name a single specimen which differs so widely 

 in form from the ordinary type of Nucula proximo, that it could well 

 be taken for a distinct species if it had occurred in large numbers or 

 in a remote locality. It is broad-ovate or elliptical in form and much 

 less angular and oblique than the typical proxima. It is decidedly 

 compressed with the umbos much less prominent than usual. The 

 surface is glossy, grayish white, marked with distinct lines of growth 

 aud microscopic radiating strine. The anterior end is evenly rounded 

 and more produced than in proxima; the ventral margin is broadly 

 and evenly rounded; the posterior end is obtuse, slightly produced and 

 scarcely augulated; the postero dorsal margin is convex and slopes 

 much less rapidly than in proxima, so that the posterior end is more 

 evenly rounded aud broader. Internally the margin is plain. The 

 hinge-teeth are much as inproxlma, but the two series are less curved 

 and meet in a broad angle. 



Length, 3.5 mm.; height, 3 mm. 



One live specimen (No. 73407), station 863, in Vineyard Sound, off 

 Cuttyhunk, in 18 fathoms, 1880. 



NUCULA SUBOVATA, new species. 

 (Plates LXXXI, fig. 8; LXXXIII, fig. 5.) 



Shell small, broad-ovate, with somewhat prominent umbos, and 

 rather acute, somewhat prominent beaks behind the middle. Surface 

 smooth and lustrous, covered with rather regular, concentric lines of 

 growth, which are scarcely visible to the naked eye. Epidermis thin, 

 pale yellowish green. The autero-dorsal margin is nearly straight at 

 first; then, forming a convex curve, slopes gradually to the bluntly 

 rounded anterior end which is somewhat produced but not angulated; 

 the postero-dorsal margin is convex, sloping rapidly, and forms a slight 

 rounded angulation iu the middle of the posterior end, where it joins 

 the broadly rounded, ventral margin. Hinge-margin rather broad and 

 strong in proportion to the size of the shell, with a moderately large 

 rounded, slightly oblique chondrophore projecting considerably within 

 the margin. The portion of the hinge-plate behind the beaks is con- 

 siderably shorter than that in front and bears about six, strong, 

 V-shaped teeth of which the two distal ones and the two proximal ones 

 are much smaller than the others; in front of the beaks it is broad and 



