460 CRETACEOUS PELECYPODA 



numerous decussating stride ; the beak is always equally strongly incurved as in the 

 other valve. In both the pallial margin is finely crenulated all round, and at the 

 ventral side, where near the hinge, it is reflected over a portion of the ligamental 

 furrow and the beaks, is finely striolated. The muscular scars are irregularly 

 excentric, being situated somewhat near the ventral margin, excavated, and their 

 upper edge begins almost immediately below the region of the beaks. 



The Indian specimens, in which the ribs are not present on the dorsal slope of the 

 larger valve, perfectly agree in general character with European ones, particularly 

 with those from the Pyrenees mountains, described by Leymerie as Ilxogyra 

 pyrenaica. Even in specimens of this form, for which we are indebted to 

 Prof. Hebert, I can, however, observe an indication of slight folds or ribs on the 

 larger valve, and this seems to make it doubtful whether Coquand is correct in 

 all the references quoted as synonyms of the three closely allied species, Ux. 

 ostracina, f= auricularisj, JE, Matheronana et E. plicifera. 



Localities,— Yjl^^^uA^, south-east of Kaudoor, east of NuUaenaccary, Arria- 

 loor, Valore, &c., &c., mostly in a softish grey sandstone, at the last named 

 locality in a white calcareous rock. 

 Formation, — Arrialoor group. 



In Europe JEx. ostracina has been found at a great number of localities, in 

 Prance, Germany, Sweden, Austria, Eussia, &c., in upper cretaceous beds (etage 

 Campanien of Coquand); in similar strata the species has also been met with 

 in North and South America, in North Africa, and in Syria and Palgestine ; in 

 India it is also a characteristic fossil of the uppermost beds of the series of 

 the Trichinopoly deposits, the Arrialoor group. 



3. EXOGYHA LACINIATA, Nilssofi, PI. XXXVIII, Figs. 1 3. 



1827. CJiama laciniata, Nilss., Petrsef. Suec, pi. viii, fig, 2. 

 1869. Ostrea laciniata, apud Coquand, Mon. Ostr. cret., p. 55. 



Ex, testa irregulariter elongato ovata, valva majore valde convexa, medio 

 longitudinaliter gihhoso carinata, lateraliter prope umbonem sessili, in declivitate 

 convexa radiatim sparse crasse-costata, costis irregidaribus, curvatis, lamellose 

 nodosis, ad marginem plus mimisve projicientihus ; umhone valde intorto, nonnunquam 

 indistincto ; valva minor e planata aut modice concava. 



Of this interesting species only a single specimen exists in our collection 

 from South India. The species is readily recognised by the ovate, inflated form 

 of the larger valve and by the few strong ribs which are very prominent on its 

 upper or convex slope, while on the ventral side the shell is generally more 

 irregular, being attached near the beak. Coquand already quotes this species 

 from Verdachellum. 



Locality, — Ninnyoor, in a light brown sandy limestone. 



Formation. — Arrialoor group. 



In Europe Fx. laciniata has been found in the upper cretaceous beds (Cam- 

 panien of Coquand) of various parts of England, Prance, Germany, and Sweden. 



