TELLINOMORPHA CUNEIFORMIS. 433 



Observations. — This species was described by de Koniuck under tlie generic 

 term Ghsenomya. I have shown in mj observations on the genus Tellinomorpha that 

 the shells which he included under the genus Ghsenomya possess a set of characters 

 totally different from those which the authors of the genus assign to it. De 

 Koninck gives ten figures of the species {op. cit.), mostly of casts, and he states 

 that a single testiferous example only has been found. 



It cannot be said that the British specimens are at all satisfactory, but 

 PI. XLIX, fig. 4, in the collection of the Geological Survey, Jermyn Street, is a 

 testiferous example, though only the anterior three-fourths of the shell is preserved. 

 The Irish specimens are also very incomplete. 



T.JHCunda bears some relation to Allorisma Ansticei, Sow., sp., but the latter 

 species is comparatively much more transverse, and has a deeper oblique sinus, 

 and never attains to such dimensions as T. jucunda. 



Tellinomorpha CUNEIFORMIS, ds Koiiinck, 1885. Plate XLIX, figs. 5 — 9. 



Tellinomoepha cuneifoemis, de Koninck, 1SS5. Ann. Mus. Roy. Hist. Nat. 



Beige, vol. xi, p. 91, pi. xxi, figs. 1, 2. 



Specific Characters. — Shell of medium size, transverse-ovate, inequilateral, 

 compressed. The anterior end is short, moderately tumid, with a rounded border, 

 passing with regular curve into the inferior margin, which is very feebly convex, 

 and may even be sinuous in the middle third, but becomes strongly curved 

 posteriorly where it passes without a break into the well-rounded posterior border. 

 This is only slightly deeper from above downwards than the anterior ; there are 

 no postero-superior or postero-inferior angles. 



The hinge-line is arched, the posterior portion being gradually depressed. 

 The umbones are small, incurved, contiguous, and swollen ; very little raised 

 above the hinge-line, and placed in the anterior third of the valve. The lunule is 

 narrow and elongate. The escutcheon, broad and shallow, is bounded anteriorly 

 by a low ridge, which passes from the umbo to the posterior border. The inner 

 edge of the valve, at about one-third of its distance from the posterior end, is bent 

 gently outwards, so that opposing edges of the valve are not in contact. The 

 valve is curved on itself from above downwards and convex ; but from before 

 backwards' the valve is on the whole compressed, commencing in front with a fair 

 amount of convexity; the middle third of the valve is markedly compressed by a 

 broad shallow groove, which commences above at the umbo, and becomes broader 



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