174 CRETACEOUS PELECYPODA 



\J 7. Cytherea [Callista] eabulina, Stoliczka, PL XYI, Pigs. 31-33. 



Cyth. testa ovato elongata, incBquilaterale^ umbonihus prominuUs, acutiuscuUsy 

 incurvis ac approximatis instructa^ declivitate lunulare fere recta^ areale convexius- 

 cula, lunitla elongata^ antice acuta^ linea impressa marginata, medio elevata ; area 

 angustissima^ paululum profunda ; terminatione anteriori rotundata^ posteriori 

 rotundate truncata ; margine ventrale uniforme curvato ; valvis moderate convexis 

 tn superficie confertissime liratis^ HaHs crassiusculis, obtusiusculis, interspatiis pro^ 

 fundis, vix angustiorihus, intersectis, Cardo in valva dextra dentihus tribiis car- 

 dinalibus, longis, tenuibus instructiis^ dente postico ftircato ; fossa lunulari elongata^ 

 angitstata ; fulcris tenuibus. 



Length of largest specimen ... , , , , , . 23 m. m. 



Height : length ... ... ... ... 0-72 - 0*79 



Thickness : height ... ... ... ... 0-51 - 0'53 



The numerous yery distinct and very regular concentric ribs give this shell 

 quite an elegant appearance; it greatly -resembles d'Orbigny's K sub-fava, Ae^^ 

 cribed and figured in the Pal. Pran9aise under Sowerby's name F. fava, which is, 

 however, a more regularly elliptical shell with finer striation. D'Orbigny's figure 

 also represents a slightly higher shell with a more oblique terminal declivity posteriorly 

 than seen in our Indian form. In this the lunula is oval, pointed in front, elevated 

 in the median line and margined by a deep groove ; the area is very narrow and 

 slightly excavated. The hinge-teeth of the right valve are rather elongated, 

 thin, the posterior being distinctly grooved ; the lunular pit is narrow, somewhat 

 elongated, with a more strongly raised edge below than above ; the fulcra are very 

 thin and situated at the base of the area, but are considerably shorter than this one. 



Localities. — Garudamungalum, (one specimen), in a bluish calcareous sand- 

 stone full of little shells; east of Odium, (four specimens), in a dark brown calca- 

 reous rock, also with small shells. 



Formations. — -Trichinopoly and Ootatoor groups, 



y 8. Cytheeea [Callista] laciniata, StoUczlm, PL VII, Pigs. 5-8. 

 Cyth. testa oblonga sen siib-quadr angular e, paulo longiori quam alta, incBqui-^ 

 lateralis convexiuscula^ antice breviter et late- postice paululum anguste ac oblique 

 truncatim rotundata ; margine ventrali leviter convexiusculo ; umbonibus prominulis, 

 ap)proximatis, sublcevigatis ; declivitate lunula^^e precipita, subrecta ; lunula angusta, 

 depressione lineali indistincta marginata ; declivitate areali convexiuscula, area 

 angusta, profunda ; cardo in valva dextra dentibus tribus cardinalibus, medio crassis- 

 simo et dente lunulari elongato insti^uctus ; superficie liris crassis, obtusiusculis, sulcis 

 angustioribus profundis separatis, notata. 



Length of largest specimen ... ... ... 20 m. m. 



Height : length ... ... ... ... 0'78 - O'SS 



Thickness: height ... ... ... ... 0-59 - 0-61 



This small species is well characterised by its great height in proportion to its 

 ength, its form being either broadly oval or sub-quadrangular, the beaks are as 



