OP SOTJTHEEN INDIA. 179 



attenuatis ; declivitate antica infra umbones parvulis adpressis paululum excavata^ 

 delude uniforme in convexitate marginis anterioris transeimte ; declivitate postica 

 fere recta, levissime curvata et cum terminatione postica angulum ohtusum 

 formante ; lunula hand distincta ; area longa, profunda; fulcris crassis et ligamento 

 prominente ; sinu pallii angusto, rapide ascendente, apice obtuse acutiusculo ; super- 

 ficie striis subtilibus numerosissimis ac nonnulUs sulcis magis profundis sed non 

 precipue latis tecta, 



Lengtli of largest specimen ... ... ... ... 54 m. m. 



Height : length ... ... ... ... O'SO 



Thickness : height ... ... ... ... 0*43 



Shell elongately and broadly ovate, rather compressed, thickest about the 

 middle, and sloping regularly towards the attenuated and sharp margins (except 

 near the area), and also towards the beaks which are somewhat depressed and very 

 close together. There is no special lunula, but the lunular region is slightly concave 

 below the beaks, passing immediately into the curve of the somewhat produced 

 anterior end ; the ventral margin is also slightly curved and the area still less so, 

 the latter forming thick obtuse edges along the extended area ; the posterior end is 

 broadly and somewhat roundly truncated. The surface of the shell is covered with 

 concentric striae, among which some are stronger than others, but the intermixed 

 sulci are not particularly broad. The pallial sinus when compared with that of the 

 next species is narrower, slightly longer, and more rapidly ascending. 



Localities, — East and south-east of Anapaudy, north of Alundanapooram, 

 and south-east of Arrialoor, in a brownish, or (at the last loc.) in a whitish sand- 

 stone; rare. 



Formations. — Trichinopoly and Arrialoor groups (only one specimen from the 

 latter) . 



y/ 2. Oypeimeria Oldhamiana, Stoliczha, PL V, Kgs. 24-25, and PL VI, Pigs. 1-5. 



Cyp. testa fere orbiculata, undique ad margines rotundata, declivitate lunulare 

 infra umbones paululum concaviuscula, declivitate areale moderate curvata ; umbo^ 

 nibus parviSi acutis et approximatis ; lunula haud marginata ; area longa, margi- 

 nibus suh-acutis ac fulcris crassis vix prominentibus instructa; valvis in medio 

 convexis atque margines versus undique declivis, concentrice regulariter ac confertim 

 striolatis, striis sulcis latioribus nonnullis ad intervalla interruptis, Cardo in valva 

 dextra duobus dentibus cardinalibus divergentibus penitus divisis, in valva sinistra 

 tribus, dente postico tenui, fossa lata ab alteris duobus anterioribus compressis ac 

 valde prominentibus separato, inst^'uctus ; sinu pallii profundo, latitisculo, oblique 

 ascendente. 



Length of largest specimen ... ... ... ... 56'5 m. m. 



Height : length ... ... ... ... 0*90 - 0'95 



Thickness : height ... ... ... ... 0'43 - 0-49 



This is one of the finest shells occurring in the South Indian cretaceous 

 deposits. Its rounded discoidal form, with slightly prominent umbones, thickest 



