TRIBE NYMPHACEA. 73 



with the umbones darker : ligameut lai'ge : cardinal teeth small, no 

 lateral ones. ^ ^^^ 9. — Arctic Occan.^ 



TELLINIDES. 



Transverse, inequilateral, Jiuttenccl, a little (/aping laterally ; 

 beaks small and sub- depressed : no anterior irrefjular plait; 

 two divergent primary teeth in each valve, and two lateral teeth, 

 which are somewhat obsolete; the posterior one approximate in 

 one valve. 



T. TiMORENSis. Lam. \.— Reeve, t. 56, f. 2. — Sow. G. — 

 Teluna Nivea. Wood. G. C. t. 46./. 1.?— i).p. 89.? — TF. t.A. 

 _/". 62.? Oval elliptic with the anterior side rather longer narrower and 

 obtusely truncated at the tip, white and but little convex, marked 

 with concentric striae and the ventral margin sindulated. \^. — Near 

 Tivior."^ 



T. Truncatulus. Sow. Tank. Cat. Oblong, anteriorly slightly 

 shorter, sub-attenuated and obtusely angulated, posteriorly rounded, 

 the ventral edge little arcuated ; smooth, glossy, sub-irridescent, 

 pellucid, sub-equivalve, convex. ^ . . \^. — li^. Indies. 



T. Opalina.— Teluna 0. Ch.f. \Q7.—Gmel. p. 3236.— TF. 

 t. 4.f. 41. Sub-ovate, posteriorly rather shorter and rounded, ante- 

 riorly obtusely sub-cuneiform, sloping uninterruptedly from the ar- 

 cuatedligamental edge to the ventral which is sub-incurved anteriorly, 

 compressed, thin, white more or less opaline, nearly smooth ; the 

 flatter valve with an internal oblique radiating rib. — Variety. 

 Rose colour. T. Rosea. Sow. G.f. \.— Reeve t. 56./. 1. 1.. 1^. 

 — Nicobar. 



T. OvALis. Sow. Tank. Oval, rounded at both ends, smooth, 

 inequivalve, anteriorly rather shorter and narrower ; thin, rather 

 compressed, pink with narrow_white rays : a solid bifid cardinal 

 tooth in one valve, an approximate lateral tooth with rudimentary 

 cardinal in the other. 



T. AcuMiNATUS. Very inequivalve, very inequilateral, oblong, 

 anterior side cuneiform and twice as long as the rounded posterior : 

 white with usually an orange tinge on the discs, thin, polished, 

 smooth except on the posterior slope where the strise of growth are 



' See also the Inflata of Chemnitz (W. t. 3./. 9.) whose figure 

 we have copied, but are unable to identify the shell. 



2 I have almost confined myself to a description of the species 

 enumerated by Mr. Sowerby, in a genus whose institution almost 

 every writer has condemned. Many, however, of the Tellens at the 

 close of the first division, have perhaps an equal right to be included 

 in this genus. 



