72 



EARLY TERTIARY OSTRACODA 



Anteromedian 



Posteromedian 



Posterior 



Dimensions (mm). 



Conical tooth with 

 straight anterior in 

 dorsal view. 

 Denticulate bar. 



Deep socket, slightly 

 elongate, open in centre. 



Deep socket. 



Locellate shelf, only 

 detectable in best pre- 

 served specimens. 

 Pessular tooth, tending 

 towards reniform in some 



specimens. 





L 



H 



w 



o-6i 



0-30 



0-29 



o-54 



o-33 



0-29 



0-52 



o-34 



— 



o-54 



0-32 



— 



o-54 



o-34 



— 



o-5i 



0-29 



— 



Io. 4303 Carapace male 



I°- 4355 Carapace female (holotype) 



Io. 3149 Left valve female 



Io. 3148 Right valve female 



Io. 3149 Left valve female 



Io. 3146 Right valve female 



Comparison. This species is perhaps ancestral to Stigmatocy there portentum sp. 

 nov. which it resembles very closely, but differs in being smaller, having deeper 

 reticulations and less prominent subcentral-tubercle. 



Remarks. The present species occurs abundantly in the Shales with Alabaster 

 of the Rakhi Nala, Zao River and Shpalai Khwara sections and seems to be restricted 

 to this formation. It is very likely that this species will prove to be a valuable 

 horizon marker in the region. 



The longitudinal ridges in some of the specimens from the upper few horizons of the 

 Rakhi Nala section are exaggerated and in some the dorsal and ventral ridges 

 posteriorly terminate in spines. This is regarded here as specific variation. 



Stigmatocy there portentum sp. nov. 

 (Plate 36, figs. 3-6, 10) 



Derivation of name. Latin portentum, omen or sign ; with reference to the 

 diagnostic ornamentation. 



Diagnosis. A large, reticulate species of the genus Stigmatocy there with three 

 distinct longitudinal ridges, prominent subcentral-tubercle. 



Holotype. Io. 4357, a male carapace (PI. 36, figs. 3-6). 

 Paratypes. Io. 3144 + Io. 3145. 



Material. Eight specimens from the locality below from two horizons (sample 

 nos. 3498 and 3499). GSP BM 2551. 

 Type locality. Rakhi Nala section. 

 Type horizon. Lower Chocolate Clays, sample no. 3498. 



Description. Carapace subrectangular in side view with the greatest height at 

 the anterior cardinal angle and the greatest length above mid-point. Anterior 



