OF SOUTHERN INDIA. 171 



3. Cythekea Arcotensis, Forbes, sp., PL XVI, Pig. 34. 



1846. Venus Arcotensis, Forbes, Trans., Greol. Soc, London, vii, p. 146, pi. xv, fig. 19. 

 1850. Astarte id., d'Orbigny, Prod, ii, p. 238. 



" Testa orbicularly subobliqua, incequilaterali, plus minusve convexa, polita 

 eoncentrice striata, striis confertis irregularibus, margine Icevi, umbonibus prominentia 

 bus J lunula minutaJ'^ (Forbes loo, cit.J, 



Sucli is the account of this species giyen by Porbes. I cannot identify it with 

 any of onr Indian shells, and, therefore, reproduce his figure. It is a remarkably 

 orbicular form. I examined the original specimen in London, and find in my 

 notebook the only remark, "figure of Porbes good; it is not an Astarte, as 

 suggested by d'Orbigny, but a CytJierea, with three cardinal and one lunular 

 tooth in the left valve, the last not very oblique and with its base close to the 

 most anterior cardinal." I thought that the species could be Cyth, plana, but the 

 form does not at all agree with it ; nor could it be Cyprimeria OldJiamiana, which 

 has nothing like what could be mistaken for a lunular tooth in the left valve. 

 It is to be hoped that further discoveries will elucidate this point. The only species 

 remaining with which it could be compared are those of the Circe group. 



" Locality, — Trichinopoly." 



iX 4, Cytheeea lassula, StoliczJca, PL VII, Pigs. 10-17. 



Cyth, testa elongato-ovata, tumescente, umbonibus prominulis, acutis, approxi- 

 matis et paululum i^curvis instructa, antice rotundata, postice angustatim truncatula ; 

 declivitate superiori antica (seu lunulari) brem, moderate excavata, postica (seu areali) 

 longiori, convexiuscula ; margine inferiori convexo, versus terminationem posticam 

 paululum insinuato ; superficie striis concentricis sulcis nonnullis latioribus interpositis 

 notata, striis minutis aliquando obsoletis ; lunula ovato-elongata, antice acuta, linea 

 impressa marginata, fere plana. Cardo in utraque valva dentibus car dinalibus plus 

 minusve distincter furcatis (imprimis dent, posticis) instructus ; dente lunulari in vaL 

 sinistra tenui, elongato, margini lunulari parallelo, in valva dextra fossce elongates 

 supra ac infra crassiuscule marginatce congruente ; sinu pallii brevi, obtuso, 

 ascendente. 



Lengtb of tlie largest specimen ,., ... ... 36 m. m. 



Heiglit : length ... ... ... ... 077 -0-83 



Thickness : height ... ... ... ... 0*60 -0'64 



Shell elongated, ovoid, rather tumid and strong, covered with fine concentric 

 striae, which in places, especially towards the margin, alternate with broad sulci ; 

 sometimes the finer striae become quite obsolete, but this is likely only due to the 

 preservation of the surface. The beaks are prominent, pointed, close together and 

 slightly incurved towards the long, elliptical lunule, which is very little raised or 

 flat, but margined with a deep line. The lunular margin is slightly concave, the 



