ISO 



CEETACEOUS PELECYPODA 



in the middle and gradually sloping towards all the margins, the regular striation 

 intersected by a few deeper sulci are all most characteristic, readily distinguishing 

 it from the last species. The pallial sinus is deep, rather rapidly and obliquely 

 ascending from the infero-posterior end upwards. The hinge is typical of the 

 genus. The right valve has two diverging perfectly divided cardinal teeth ; the 

 left two compressed very prominent anterior cardinals and one thin posterior, 

 separated from the former by a broad but along the centre again somewhat raised 

 groove ; this posterior tooth is connected with the broad and thick fulcrum. There 

 is no trace of a lunular tooth, though that portion of the margin is broad, but 

 it is slightly excavated in both valves. 



The common European Cijp. discns, Math., is more compressed, and has the 

 beaks almost always remarkably flattened. 



Localities.— Ana])a\u\j, north of Alundanapooram and Garudamuugalum, in 

 a brownish, whitish, or bluish calcareous sandstone ; not rare. 



Formation. — Ti-ichinopoly group. 



3. Cyprimeria obesa, cVOrUyny, sp., PI. XVII, Figs. 1-2. 



1847. Lticina ohesa, d'Orbignj-, Paleont. Voy. FAstrokbe, pi. v, figs. 26-28. 



Cup. testa qnadranfftihn'iter rotunclata, valde iiijlata, concentrice striis mtmerosis 

 suhtilissimis ac sidcis latioribus ad intervalla interjiositis notata ; umhonihus obtusius- 

 cidis, paulo prominidis, inciirvis ; regione lunulare infra umhones vix excavate, 

 decUmtate areale fere rectitiscula, marginibiis ceteris unforme curvatis; area brevi, 

 angiistissima ; cardo in valva dextra duobiis dentibiis divergentibus omnino dicisis, 

 2)Ostico multo crassiore instructus. 



Specimen figured on pi. xvii, fig. 1. 

 HeigM : length ... ... 0'88 



Thickness : height ... ... 0-72 



Specimen figured by d'Orbigny, pi. \v\\, fig. 2. 

 Height : length .., ... 0-93 



Thickness : height ... ... 0'78 



D'Orbigny gives an enlarged figure of a small specimen, but it evidently 

 represents the same species as the one here described, though the roundness and 

 thickness are slightly larger, which, however, is not unusual in young shells, theii- 

 convexity generally becoming less prominent as they grow in size. The only 

 ri"'ht valve which we possess is apparently a little less tumid, because the surface 

 is just in the place of the greatest convexity slightly worn off. The two diverging 

 teeth of the right valve are perfectly divided, and the posterior tooth is thicker 

 than the anterior, which is also somewhat less indistinctly traceable ; the lunula 

 iSj as usual in Cyprimeria, not margined, and the area is small and very narrow. 



Locality. — Is innyoor, in white limestone ; apparently very rare. 



Formation. — Arrialoor group. 



