NO. 1237. ^ YXOPSIS OF THE L UCINA CEA—DA LL. 819 



long, very narrow, bordered externally by a sharply incised groove; 

 behind this a rather shallow sulcus radiates from the beak, bounded 

 behind by a rounded radial ridge; ligament thin, delicate, set in a nar- 

 row groove; margins reflecting the external sculpture, beaks narrow, 

 prosogyrate, inconspicuous. Lon. 14.5, lat. 13.0, diam. 9 mm. 



Several valves came up with mud on the anchor from a depth of ten 

 fathoms in the roadstead of Tome, Chile. 



THYASIRA MAGELLANICA, new species. 

 (Plate XLII, fig. 6.) 



Shell small, white, subovate, moderately convex, with rather high 

 and prominent beaks; external surface sculptured with faint incre- 

 mental lines and shallow, ill-defined radial sulci; lunule small, moder- 

 ately impressed, but without any well-dehned bounding ridges; escutch- 

 eon narrow, obscure; just in front of it a shallow sulcus radiates from 

 the beaks to the basal posterior margin; hinge edentidous, ligament 

 feeble. Alt. 4.T, lat. 3.5, diam. 3.0 mm« 



A single valve was obtained on the west coast of Patagonia in 194 

 fathoms, nuid, the bottom temperature being 52^ F. 



This species appears to differ from T. fueglens'is Dall by its more 

 elevated form, smaller size, and especially by the position of the pos- 

 terior radial sulcus, which, though feel)le as in that species, is situated 

 much closer to the posterior dorsal margin. 



AXINOPSIS SERICATUS (Carpenter). 

 (Plate XL, tig. 2.) 



I have figured a typical specimen of Carpenter's shell for comparison 

 with the following form, and also because the former has never been 

 figured. Both the West American species are more solid shells and 

 have the cardinals much better developed than the A. orhlcidatux, Sars 

 of the North Atlantic. The specimen figured is from Puget Sound, 

 where it was dredged by Dr. Kennerly. 



AXINOPSIS VIRIDIS, new species. 

 (Plate XL, fig. 1.) 



Shell small, polished, suborbicular, when fresh covered with a glis- 

 tening pale-green periostracimi, some times exhibiting lighter and 

 darker concentric zones; sculpture solely of fine concentric lines of 

 growth; beaks low, inconspicuous; lunule slightly impressed, but with- 

 out any bounding sulcus or ridge, small, sublanceolate; escutcheon 

 hardly recognizable, very narrow, and inconspicuous. The part of the 

 lunule belonging to the right valve is slightly larger than the other. 

 The ligament is small and very delicate, but not wholly concealed. The 



