218 Cr.ETACEOUS PELECYPODA 



4. Caudium [Acantiiocakdium] pullatum, SloUczka, PI. XI, Figs. 8-10. 



Acanth. frsta parvnla, rotundate quadranytihiri, v(dde iujlata, cUmsa, fere 

 (equilatcrali, aniice ad marginem lente curvaia, jwsticc suh-recta ; siiperficie costiilis 

 circiter 28-30 radiantibus, aqnidistantibtis, aciit'msculis, tnbercuUs mimerosia sub- 

 spimdosis notatis ornata ; area cardinali moderate curvata, dentibus rer/ularibiis 

 inslructa. 



Height of slic'U : its length ... ... ... ... 0-92 



Thickness „ : „ ... ... ... ... lOO-Otlo 



This species has in general character a much greater resemblance to C. Oltoi, 

 Geinitz, than the last, but the former has the radiating ribs ornamented with 

 transverse thin lamellae, not with tubercles, as in C. pullatum, and is also somewhat 

 less inflated than the present species. When the surface of the shell is a little 

 worn off, the ribs appear to be almost smooth (fig. 9), and then the form of the 

 shell becomes more rounded. The hinge-teeth are of moderate size and sharply 

 pointed. 



Jjocalities.—'N eighhoixrhood of Vylapaudy and Anapaudy, partially in a brown- 

 ish calcareous rock, partially in light coloured sandstone ; rather rare. 



Formation. — Trichinopoly group. 



5. Cardium [Cerastoderma] pilatum, Stoliczka, PI. XIII, Pigs. 6-7. 



Cerast. testa sub-orbimlata, moderate injlata, ina^quilaterali, tenui, postice late 

 rotundata ; superficie costtdls radiantibus numerosissimis, latiusculis, sub-lavigatis, 

 interdum squamulose granulans siilcis a^igustissimis disjiinctis ornata ; lunula Icevi- 

 nscula, extus hand marginata ; cardine dentibus cardinalibiis jxtrvis, lateralibus 

 lamellosis instructo. 



Height of shell : its length ... ... ... ... 0-95 



Thickness „ : „ (appiMximateU) ... ... ... 078 



This is the only South Indian species which appears to belong to the sub-genus 

 Cerastoderma, though it is rather too much rounded, but it is distinctly consider- 

 ably shorter anteriorly than posteriorly. The surface is ornamented with very 

 numerous flattened radiating ribs, separated by grooves much narrower tlian the 

 ribs ; these arc in young specimens ornamented with fine lamellar tubercles, which 

 seem to become obsolete with age ; the lunula is smooth. 



Locality. — Ninnyoor, in white soft limestone. 



Formation. — Arrialoor group. 



