942 DR. GWYN Jeffreys on the mollusca of the [Nov. 29, 



y 14. Ne^ra circinata, Jeffreys. (Plate LXXI. fig. 6.) 



N. circinata, Jeffr. in Ann. & Mag. N. H. Dec. 1876, p. 497. 



♦Porcupine' Exp. 1869: St. 23 (a fragment). 1870: Atl. 16 

 (a small valve). 



Distribution. Bay of Biscay ('Travailleur ' Exp.), N. Atlantic 

 (' Valorous ' Exp.), W. of Azores ('Challenger' Exp.); 600-1450 

 fms. 



N, imbricata, Jeffr. MS., is a synonym. 



15. Ne^ra ruginosa', Jeffreys. (Plate LXXI. fig. 7.) 



Shell roundish-oval, somewhat depressed, thin, semitransparent, 

 and rather glossy : sculpture, numerous fine and concentric minute 

 striae, which become wrinkly towards and on the posterior side : 

 colour white : margins rounded equally ou the anterior side and in 

 front ; rostrum very short and obliquely truncated ; dorsal margin 

 lying beneath the umbo, short and scarcely curved on the anterior 

 side, half as long again and straight on the other side : healcs mi- 

 nute, circular, and sunken ; umbo small and prominent : cartilage- 

 pit minute, narrow, and placed obliquely : hinge-line na^ciXy straight : 

 hinge-plate thin, slightly reflected on the anterior side : teeth, none 

 in the left valve, the right valve not having been found : inside 

 polished : scars inconspicuous. L. O'l, B. 0*15. 



'Porcupine' Exp. 18/0: Atl. St. 17, 17a. Three left valves 

 only. _ 



This small species might be mistaken for the young of N. circi- 

 nata ; but the sculpture is very different, and the rostrum is much 

 shorter. 



^ 16. Ne^ra inflata^ Jeffreys. (Plate LXXI. fig. 8.) 



Shell equivalve, roundish-oval, with an oblique outline, gaping 

 posteriorly, globose, rather solid, semitransparent, and glossy : sculp)- 

 ture, very numerous, fine, and close-set concentric striae, which are 

 observable with the naked eye ; they are more irregular and some- 

 times wanting, or become wrinkly, on the rostrum : colour pale 

 yellowish-white : epidermis filmy : inargins rounded on the anterior 

 side and in front ; rostrum short and bluntlj^ pointed, appearing as 

 if pinched up, and separated or defined by a shallow indentation ; it 

 is occasionally somewhat angulated and marked by a slight keel or 

 ridge, which is more distinct in the young ; dorsal margin upraised 

 on the anterior and down-sloping on the posterior side : becds tri- 

 angular, incurved towards the anterior side; umbones very prominent : 

 cartilage-pit oblong, narrow, and obliquely j)rojecting inwards : 

 hinge-line obtuse-angled : liinge-plate thin, a little reflected ante- 

 riorly : teeth, a small upright triangular cardinal and a long laminar 

 lateral on each side in the right valve, besides a long laminar lateral 

 on the posterior side, and parallel with the hinge-plate in the left 

 valve : inside polished, furnished on the posterior side in each valve 

 with a strong and curved laminar process or ridge, which apparently 



» Wrinkled. * Swollen. 



