48 EARLY TERTIARY OSTRACODA 



ridge which posteriorly joins the dorsal and ventral ridges and the palmate appear- 

 ance of ridges in front of the subcentral-tubercle. Moreover, the greatest width in 

 Hermanites palmatus is in the posterior third, but in Hermanites purii it is a little to 

 the anterior of the middle (see Tewari and Tandon, p. 158). 



Remarks. The true relationship of the present species with Hermanites indicus 

 and Hermanites purii cannot be determined until topotype material from Kutch is 

 available for comparison. 



Genus OCCULTOCYTHEREIS Howe 1951 

 Type species. Occultocythereis delumbata Howe 195 1. 



Occultocythereis interrupta sp. nov. 

 (Plate 24, figs. 10, 13-18) 



Derivation of name. Latin interruptus, broken apart ; with reference to the 

 break in the dorsal ridge. 



Diagnosis. A small Occultocythereis with well-marked subangular postero- 

 dorsal process which is confluent with four ridges including an oblique ridge running 

 towards posteroventral region and then extending towards anteroventral corner as 

 an oblique ventral ridge. 



Holotype. I04339, a female carapace (PI. 24, figs. 14, 17, 18). 



Paratype. Io. 4287. 



Material. 28 specimens from the locality below from three horizons (sample 

 nos. 460-f, 460-i and 460-j). GSP BM 2556-7. 



Type locality. Sor Range section. 



Type horizon. Upper Palaeocene, sample no. 460-i. 



Description. Sexual dimorphism marked ; the females are shorter and wider 

 than the males. Carapace subrectangular in side view, tapering towards the 

 posterior. Dorsal and ventral margins almost straight ; the dorsal margin appears 

 slightly irregular in lateral outline because of the over-reaching of the dorsal ridge ; 

 anterior margin broadly and obliquely rounded, posterior narrow, slightly concave 

 in posterodorsal slope but more or less rounded in posteroventral margin. Greatest 

 length lies through the mid-point and greatest height at the anterior cardinal angle. 

 Anterior and posterior cardinal angles well-marked particularly in the right valve. 

 Valves almost equal. Eye-tubercle distinct, situated on the anterior marginal rim. 

 Shell surface undulating with compressed anterior and posterior platforms. A well- 

 marked, subangular posterodorsal process is confluent with four ridges : (1) a short 

 ridge extends vertically towards the posterodorsal corner ; (2) a dorsal ridge runs 

 towards the anterior, culminating in the anterior third of the dorsal margin — it is 

 slightly convex upwards ; (3) a short ridge extends vertically below, terminating 

 before reaching the mid-line, whilst the fourth ridge runs obliquely towards the pos- 

 teroventral region where it is joined by an oblique ventral ridge running towards 



