OP SOUTHEEN INDIA. Ml 



mulose sub'tuherculatis aut confertis^ et cequidistantibm^ aut paucioribus et sub-dis- 

 tantibus^ omnibus simplicibus ; valva supera planO'Concaviuscula, ad umbonem 

 paululum tumidula^ distinctius auriculata^ primo radiatim granulato striata^ postea 

 costulata^ costulis Us m valva altera smilibus. 



The lower valve is in this species always convex, truncate, and attached at the 

 beak with a larger or smaller area. The upper valve is variable ; on the whole, it is 

 concave, but the upper part, corresponding to the place of attachment, is either 

 plain or slightly tumid. This portion of the valve is also differently ornamented 

 from the rest. The radiating lines on it are thin and finely granular, while the 

 remaining portions of both valves are covered with much stronger, scaly, and sub- 

 tuberculated ribs, all equal in size, but either more numerous and equidistant, 

 or in smaller numbers and, towards the periphery, more distant from each other. 

 The form of the shell greatly resembles Fl, spinosa, Mant., but the ribs are com- 

 paratively always more numerous, and less spinose. 



Localities, — Ootatoor, Odium, and Moraviatoor, in yellowish brown or dark 

 brown earthy limestone ; not common. 



Formation, — Ootatoor group. 



5. Plicatula septemcostata, Forbes, PL XLVIII, Pig. 4. 



1846. Plicatula septemcostata, Forbes, Trans., Geol. Soc, Lond., vii, p. 155, pi. xviii, fig. 4 — eadem anctorum. 



P. testa sub'Obliqua, sub-orbiculari, convexiuscula, incequivalvi, longitudinaliter 

 (z=z radiatim) costata, costis septem majoribus, sub-angulatis, fsub-squamosisj ; apice 

 affixa, (Forbes, I, cit,J, 



I am unable to add anything to the knowledge of this species ; there is no 

 specimen of it in our collection. The lower valve is slightly more convex than the 

 upper one, and both are similarly and equally strongly ribbed. 



Locality, — Pondicherry. 



Formation, — ? Valudayoor group. 



SPONDTLUS, Klein, 1753, (see p. 441). 

 1. Spondyltjs Arrialookensis, Stoliczka, PL XXXIII, Pig. 5. 

 Sp. testa oblique late ovata, valva inferiore late affixa, cupuliforme, umbone 

 moderate irregulariter producta, margine inferiore sensim elevata, radiatim costeU 

 lata et concentrice crasse lamellata; valva supeiHore convexa, versus marginem 

 deplanata, radiatim costellata et concentrice obsolete striata, cost ellis paulo incequa- 

 libus, confertis, cequidistantibus, rugulose spinulosis, posticis paulo fortioribus quam 

 anticis, nonnullis (S — 4J crassioribus et ad intervalla spinis altis, lateraliter com- 

 pressis, armatis ; auriculis magnis, sub-cequalibus, sub-lcevigatis, obsolete striolatis, 

 utraque prope marginem cardinalem, fere rectum et incrassatum, costula spinulose 

 loMiellosa instructa ; umbone obtuso, extra marginem paulo projiciente. 



The lower valve of this species is sessile with a broad surface on a fragment 

 of an Inoceramus ; it is rather low at the umbo, which is irregular, and with the 



