OF SOUTHEEN INDIA. 471 



Western Germany, in Prance, England, North America, (O. larva of Lam.), 

 Northern Africa, Poland (near Lemberg), Russia, Asia Minor, Arabia, &c. Eorbes 

 and d'Orbigny both proposed a new name for the Indian fossil, but its iden- 

 tification with the European one has been already pronounced by Ooquand, 

 a conclusion to which I also arrived already some few years previous when I had 

 an opportunity of examining Eorbes' and d'Orbigny's original specimens. 



7. OsTREA [Alectryonia] Aucotensis, Stoliczka, PI. XLIII, Eigs. 3 — 7. 



Ost. [_AleGtr.~] testa parva, irregulariter suh-ovata, incequivalvi, valva inferiore 

 modice convexiuscula, ad umbonem plus mimisve oMusatum sessili, val, sup. aut paulo 

 elevata aut planiuscula ; utraque radiatkn crasse costata, costis crassis, sub-acutis, 

 simplicibus vel dichotomis, sub-cequalibus, sub-lcEvigatis, striis nonnullis incrementi 

 distantibus transcendentibus, ad marginem oblique terminantibus ; margine ventrali 

 minute plicato, imtus multidentato, reliquo crassius dentato ; area ligamentali modica, 

 sub'triangulari, in valva inf. medio excavata, in valv. sup. plana; impress, muse, 

 excentrica, postica, haud procula margine vent, sita, transversaliter subsemicirculari ; 

 impress, pall, dorsaliter nonnu/nquami plicatula. 



A small, sub-ovate, slightly bent species, the lower valve of which is moderately 

 convex, the upper more or less flattened. Both valves are covered with numerous 

 radiating, sub-equal, somewhat obtuse, ribs, crossed at certain intervals by a few 

 lamellar striae of growth and terminating obliquely near the margin, which is 

 strongly toothed, except at the ventral side, where the denticulation is much finer 

 and more numerous than anywhere else. In ornamentation, and partially also in 

 form, this species very closely resembles Ost. Villei, Coquand, from Algiers, 

 (Monog. Ostr. cret., 1869, p. 27), and I would have identified both were it not 

 for the very different shape of the muscular scars, which in the Algerian species 

 are much more transversally elongated and placed more posteriorly. 



Localities. — South-east of Arrialoor (in grey sandstone), north of Poodoo- 

 poUiam, in a white calcareous sandstone. 



Formation. — Arrialoor group. 



8. Ostrea acutirostris, Nilsson, PL XLV^ Eigs. 1 — 6, 



1827. Ostrea acutirostris, Nils son, Petr. Suec, pi. vi, fig. 6. 

 1869. „ „ Coquand, Monog. Ostr. cret., p. 7^. 



Ost. testa aut elongata, aut irregulariter late ovata^ incequivalvi ; valva inferiore 

 sessili, convexiusGula, concentrice crasse undulatim lamellosa et striata, radiatimque 

 sub-costulata, costulis pliciformibus, cequidistantibus, scepe indistinctis et later aliter 

 obsoletis; umbone producto, rostrato, nonnunquam paulum incurvato; area ligamentali 

 medio fossula profunda instructa ; valva superiore scepissime paulum mvnore, irregu^ 

 lariter planulata aut sub-convexiuscula^ concentrice lamellata et striata, haud radiatimi 



