iis "TERRA NOVA" EXPEDITION, 



Onlv a dead valve obtained, but showing that the species occurs much farther 

 north than the original locality. 



1:1. X/iriifiiini (Adrana) I'lectn (A. Adams). 



Leda eJcctn, A. Adams, Proc. Zool. Soc., 1856, p. 48 ; Hanley, Thesaurus Conch., vol. III., 



p. 109, pi. 227, figs. 40, 41 ; Sowerby, Conch. Icon., vol. XVIII, pi. I, figs. 2A, 2u. 

 Niicula lanceoJata (Lamk. ?), Sowerby, Genera, pi. S2, fig. 1. 

 Leda (Ailrtinit) elei'ta : H. and A. Adams, Genera Moll., vol. II, p. 547. 



Station 42, off Rio de Janeiro : 40 fathoms. One broken valve only. Santos, 

 Brazil (A. Ad.). 



Larger, .smoother, and whiter than iV. janeiroensis, also differently sculptured. 



14. Xiiriiliiiui (Ailrniui) juneirnen^ix, n. sp. PL II, fig. 10. 



Shell elongate lanceolate, acumiuately rounded anteriorly, rostrate behind, a little 

 inequilateral, dirty white, concentrically finely striated or very delicately sculptured 

 with threadlike lirse, which are rather stronger near but not upon the anterior dorsal 

 slope, which is more finely striated ; they are also coarser at the rostrate end. There 

 is a smooth linear lunule defined by a delicate keel extending from the umbo a 

 considerable way towards the end of the dorsal margin ; posteriorly there is a rather 

 broader smooth escutcheon bounded by a rounded cariua, which is strongly sculptured 

 with close lamellae ; a second keel radiates from the umbo at a little distance from the 

 other, both terminating at the end of the rostrum ; the valves are moderately strong, 

 convex, and glossy white within ; teeth numerous, erect, extending about the same 

 distance on both sides of the small, broadly triangular resilium-pit. 



Length, 28 mm. ; alt., 8 ; diameter, 5. 



//<//,. Off Rio de Janeiro in 40 fathoms. Lat. 22 56' S., Long. 41 34' W. 



At first sight this species exhibits a close resemblance to N. crenifera, Sowerby,* 

 from Xipixapi, on the west coast of South America. It is, however, less acuminate 

 anteriorly, the hinder dorsal margin is more coucavely curved, the concentric sculpture 

 at both ends is a little coarser, the valves are a trine more convex, and the distinct 

 ridge or keel which borders the front dorsal margin of A", cwnifcnt is absent in this 

 species. The hinge-teeth in the former are both finer and more numerous quite fifty on 

 each side the resilium-pit whereas in N. janeiroensis there are only about thirty-eight. 



N. decora^ (A. Ad.) is similarly sculptured, but is shorter, a little more convex, 

 with a shorter hinge-line and fewer teeth than the present species. 1 feel in 

 some doubt whether they ought not to lie considered forms of the same species. 

 However, judging by the amount of material at hand, there is no difficulty in 

 distinguishing them. 



' Thesaurus Conch., vol. Ill, p. 110, pi. 227, figs. 37, 38. 

 t Thesaurus Conch., vol. TIT, p. Ill, pi. 227, figs. 47, -IS. 



