OF SOUTHERN INDIA. 405 



structure, but often they are so far worn down that to the naked eye the surface 

 appears as perfectly smooth. 



Zocaliti/. —Vondichevvy, m a bluish sandstone ; Comarapolliam and Veraghoor, 

 in a lio'ht coloiu'ed sandstone. 



Formation. — Arrialoor group. 



INOCERAMUS, Sowerbi/, 1822, (see p. 393). 



1. Inocekamus Ckipsianus, Mantell, pi. XXVII, Pigs. 1—3, and PI. XXVIII, 



Pig. 2. 



1822. Inoceramus C?'ipsn, Ma.nt., Geo\. ot Sussex, p. 133, 1)1.27, fig. 11; vide Zittel in Denksch. Akad., 



Wieu, XXV, pt. ii, p. 95. 



In. testa cBqtiivalvi, valcle iiKequilatemU, elongato-ovata, plus mimisve tumida, 

 antice breviter siib-rotimdata ; postice multo lougiore, margine convexe trimcato ; 

 margine ventrall leviter convexo, dorsali longo, recto, intiis iiicrassato et foveolis 

 numerosis ligamentalibus instructo ; mnbonibus tmnidis, hicurvis approximatis ; siiper- 

 Jicie pllcis rotimdatis, crassis, fere ceqiiklhtantlbus, et lineis concentricis coufertisshnis 

 et subtUissimis, nonnimquam paulo tindulatis, notata. 



The variations which this species exhibits in India are perfectly the same as 

 those observed in the European fossil, of which Zittel gives so many character- 

 istic illustrations. Most common is the var. typica of Zittel, of a reo-ular 

 elongated or oblong form and with strongly tumid valves (pi. xxvii, fig. 1). The 

 principal locality where this form occurs is the conglomeratic sandstone about 

 Karapaudy. 



A quite similar variety, represented in pi. xxviii, fig. 2, is characterized by a 

 lesser development of the concentric plications, and somewhat smaller and more 

 pointed beaks. This variety is found in whitish sandy beds north-east of Maithal. 



The flatter and more rounded variety (var. regularis, d'Orb.,) occurs in the light 

 grey sandstones west of Arrialoor, and attains here often very large dimensions ; 

 specimens of 150 m. m. in length and about 125 m. m. in height are here not 

 uncommon. The same variety also occurs in the fine oolitic rock at Olapaudy ; 

 and also the mytiloid variety, with the anterior side very short and obliquely 

 sub-truncate, figured by Zittel as var. decip)iens, is there associated with other 

 similar forms. 



Localities. — Olapaudy, west-east of Arrialoor, Maithal, north-west of Poodoor, 

 north-east and south of Karapaudy, &c. 



Formation. — Arrialoor group. 



I. Cripsianus is in South India a characteristic fossil of the uppermost series 

 of the cretaceous deposits, the Arrialoor group. In Europe the original form is 

 said to be from the Gault-beds of Sussex, but it has nowhere else been found 



