OF SOUTHERN INDIA. 127 



beaks are very slightly prominent, the upper margin somewhat curved, but 

 very gradually descending; the anterior side is rounded, the posterior convexly 

 truncated, with a slightly elevated, rather broad ridge running from the beak to 

 the postero-inferior margin. The surface is very elegantly and most minutely 

 concentrically striated, the strife being extremely fine, but distinctly elevated and 

 separated by broader, though deep furrows. The hinge of the right valve has two 

 distinct cardinal teeth, of which the anterior is bifid ; the posterior lateral tooth 

 is traceable, but rather distantly placed, the anterior lateral is obsolete. The more 

 rounded and shorter form readily distinguishes this species from Tell. Arcotensis, 

 and the less distinct posterior ridge and more oval shape of the shell appears to 

 agree with some recent species, like Tell, coccinea, which have been referred to the 

 sub-genus Tellmides. 



Locality. — ComarapoUiam, in a; greyish conglomeratic sandstone. 



Tormation . — Ai'rialoor group. 



5. Tellina [Arcopagia] mendosa, Stoliczka, PI. IV, Fig. 9, 



Tell, testa ohlonga, stih-compress'a, fere cequilaterall, antice late rotundata 

 postice angulata, pUcatura 2)arva bistructa ; marcjinlbm superioribus declivis, props 

 rectis ; margine Inferiori convexo, jjostice flexuoso, insinnato. Cardo in utraque 

 valva diiobiis dentibtts obliquls cardinalibns, in valva dextra duobus lateralibus 

 crassis instructus : anteriorl dentibus card'malibus approxiniato, posteriori remoto ; 

 impressionibus muscularibris magnis, elongalis ; shin pallli lalo, ad f totius tesice 

 longitudinis extenso, vix ascendente. 



Although the single specimen figured is only a cast, its form and otherwise 

 very good preservation makes the shell so characteristic that it could not easily 

 be mistaken for another species. The form is broadly oblong, about ftli longer 

 than high ; the valves are somewhat convex, the beaks prominent, with the 

 sides almost straight, sloping and forming an angle of Hi degrees ; the anterior 

 side is broadlj^ rounded, the posterior angulated, somewhat flexuous, there being 

 an indication of a small posterior plicature. There are two cardinal teeth in each 

 valve, and in the right two very strong lamellar teeth, of which the anterior is 

 thick and close to the cardinals, the posterior thin, lamellar, and I'emote ; no trace 

 of lateral teeth is perceptible in the left valve. The muscular impressions are 

 much elongated ; the pallial sinus deep, reaching to about frds of the length of the 

 shell and scarcely ascending at all. On the anterior slope of the cast there are a 

 few corrugations, and, judging from the strong impressions of the different parts, the 

 shell must have been rather solid, and, on the whole, very much like the recent Tell, 

 discus. There is no trace of lateral teeth perceptible in the left valve, but such is 

 nearly the case in some specimens of T. discus also ; the form and position of the 

 other teeth is, however, so very characteristic that I think there can be little 

 doubt of our species also belonging to the sub-genus Arcopagia, though the pallial 



