170 CRETACEOUS PELECYPODA 



I liave not seen any of the original specimens referred by d'Orbigny to 

 this speeies in his " Pal. fran9aise," but I saw others fully as short and high 

 as the one figured by Goldfuss. His figure shows the lunular edge very pro- 

 minent ; some specimens approach to it in this respect, but I have not seen any 

 with an equally strougly projecting lunula. Some of our specimens also perfectly 

 correspond with the two photographs given by Gu6ranger. The form figured by 

 Reuss (in Bohm. Kreidef., pi. xli, fig. 14,) has the anterior side very much pro- 

 duced, and if the outline of tlie posterior end is correct, I would think that it 

 hardly could belong to the present species. Our specimens are certainly undistin- 

 guishable by any prominent character from those occurring at Blackdown from 

 which Sowerby obtained his originals: both exhibit the same amount of vari- 

 ations as already stated. 



JLocalities. — North of Alundanapooram and north of Kunanore, in a yellowish 

 brown conglomeratic sandstone. 



Formation.—? Trichinopoly group, but very close to the boundary of the 

 Arrialoor, with which tlie raineralogical character of the rock corresponds rather 

 better than with that of the former. In Europe the shell appears to be charac- 

 teristic of the Upper Greensand and Senonien (Plsener) beds of the continent. 



2. Cytherea Garudana, Stoliczlca, PI. VI, Pigs. 17-19. 



Cifth. testa regitlariter ohlonga, sub-incequUaterali, crass'mscula, ad iitramqne 

 terminationem sub-rotimdata, compress'wscida imjrrimis in senioribus speciminibns ; 

 superficle striis concentricis prope marginem exteriorem crassioribus, ac sidcis latius- 

 culis notata ; lanbonibiis aciitis, paido incurvis, declivitatibus superiorihus snb- 

 rectis, antica patilultom concava, postica convexiuscula ; dentibiis cardinis sicut in 

 Cyth. plana dispositis ; lunula angtista longa, Unea impressa circumserip)ta. 



Length of largest specimen ... ... ... ... 45 m. m. 



Height : length... ... ... ... ... 0-70 -074 



Thickness : height ... ... .•■ .■• 040 -046 



Shell nearly regularly oval, rounded anteriorly and posteriorly, with the beaks 

 somewhat prominent and incurved towards the anterior end ; the surface is covered 

 with strife of growth only, these being stronger near the margins and partially 

 alternating with broadish shallow sulci; the lunule is very long, narrow, cordiform, 

 along its central line somewhat sharply elevated, and all round margined by a fine 

 groove. The hinge does not diff'er in any essential way from that of Ci/th. plana, 

 except that the lunular tooth of the left valve is proportionately somewhat stronger, 

 though the corresponding cavity of the left is not peculiarly deep and not marked 

 by such strongly elevated edges as in the former species ; the cardinal teeth of the 

 right valve are all more or less distinctly bifid. The pallial sinus has not been 

 observed. The oval and compressed form readily distinguish this from the former 

 speeies, and also from Cyth. Archiaciana, to which it appears still more related. 



Locality. — Comarapolliam, in a greyish sandstone. 



Formation. — Arrialoor group. 



