OP SOUTHERN INDIA. 431 



PECTEN, Klein, 1753, (see p. 424). 

 1. Pecten Anapaudiensis, Stoliczka, PI. XXXII, Pig. 1, & PI. XL, Pig. 6. 



1846. Pecten ohliquus, Sow., apud Forbes, Trans., Geol. Soc, Lond., vii, p. 154 — non idem Sowerby. 



P. testa ovata, paululum obliqua, incequivaM, valva sinistra convexiore, costis 

 radiantibus fortiorihus et fl-3J tenuioribus interpositis, squamose tuberculatis, ornata, 

 valva dextra planiuscula, radiatim sub-cequaliter dense costata et concentrice squamose 

 costellata. 



This species is closely allied to the European Feet, obliquus, with which it was 

 considered identical by Porbes, but it differs in the character of the ribs. On the 

 left valve, which is somewhat more convex than the right, there are 1-3 thinner 

 ribs between each two stronger ones, but they do not differ so much in strength as 

 in obliquus. On the right valve the difference in the strength of the radiating ribs 

 is still less marked, and the concentric lamellar stri^, or sharp ribs, are closer 

 together than on the left one. The cast has only slight indications of the ribs. 



In Porbes' original specimen (pi. xl, fig. 6,) the concentric strise have become 

 obsolete between the radiating ribs, and are indicated only by small scaly tubercles 

 on them. 



Locality, — East of Anapaudy, in a brownish sandstone. 



Formation, — Trichinopoly group. 



2. Pecten eaduloides, StoliczJca, PI. XXXI, Pig. 20, PI. XXXII, Pigs. 2—3, and 



PI. XLII, Pig. 6. 



Feet, testa oblique sub-orbiculari, postice lateraliter sensim dilatata, cequivalvi, 

 valvis paulo convexiusculis, radiatim costulatis et concentrice sub-obsolete striatis, 

 costulis Icevigatis, sub-undulatis, in speciminibus Junioribus cequalibus, depressiusculiSy 

 cequidistantibus, in adultis alteris tenuioribus interpositis, in declivitate postica fere 

 omnino obsoletis ; auricuUs sub-cEqualibus, postica valde obliqua, antica truncata, 

 in valva dextra ad basin insinuata. 



This is a very characteristic oblique species, in general form somewhat resem- 

 bling a Badula, having the posterior side sensibly expanded. In young specimens 

 the ribs are equidistant, smooth, depressed, and of equal strength; in older ones they 

 alternate with thinner ribs, being always slightly undulating, and on the posterior 

 declivity generally obsolete. As a rule, the ribs are equally well marked on both 

 valves, but in some specimens they are a little less developed on the left, and when 

 on this one the outer layer is not well preserved, they occasionally become hardly 

 traceable (see fig. 3 on pi. xxxii). The species is closely allied to the European 

 P. undulatus, apud Goldf., but apparently somewhat more oblique, not so wide, 

 and with more distinct radiating striation. I can hardly believe that Goldfuss' 

 species can be the same as that described by Nilsson in 1827 under the same 

 name ; the figures of both are entirely different. 



Localities, — South-west of Mulloor, west and south-east of Arrialoor, near 

 Karapaudy and near Veraghoor, in whitish or reddish sandstone. 



Formation, — Arrialoor group. 



