22 EARLY TERTIARY OSTRACODA 



MORPHOTYPE E 



(Plate 7, figs. 5-8 ; Plate 8, figs. 1-3, 5) 



This is similar in all characters to Morphotype A and Morphotype C but has a 

 papillose surface. It has a curved posteroventral margin in the male and female 

 dimorphs as in Morphotype C. There is a smooth, shallow groove on the dorsal side 

 of the ventral ridge. 



Dimensions (mm). 



L H w 



Io. 3110 Carapace male o-8o 0-46 0-46 



Io. 3111 Carapace female 0-74 0-46 0*45 



Morphotype F 

 (Plate 8, figs. 6-9 ; Plate 9, figs. 1-5) 



This has a small carapace. The surface is ornamented with slightly papillose 

 reticulae. There is a rim behind the anterior marginal rim and almost parallel to it 

 with reticulations in between. It originates from the eye-tubercle and fuses ventrally 

 with a short, oblique ventral ridge. It is likely that these forms may be juveniles of 

 Morphotype A or Morphotype C or may even belong to a distinct species. 



Dimensions (mm). 



L 

 Io. 3109 Carapace male o-68 



Io. 3108 Carapace female 0-64 



Io. 3112 Right valve female 0-59 



Alocopocythere radiata sp. nov. 

 (Plate 9, figs. 6-9 ; Plate 10, figs. 1-4) 



Derivation of name. Latin radiatus, rayed ; with reference to the ridges 

 radiating from the subcentral-tubercle. 



Diagnosis. A coarsely reticulate Alocopocythere with longitudinal ridges radia- 

 ting from the posterior of a well-developed subcentral-tubercle. Eye-tubercle 

 distinct, marginal rim high, ventral inflation ends in a marked ridge, almost parallel 

 to the ventral marginal rim. 



Holotype. Io. 4317, a male carapace (Plate 9, figs. 6, 8 ; Plate 10, figs. 1, 2) 



Paratype. Io. 4270. 



Material. 14 specimens from the locality below from one horizon (sample 

 no. 3652). 8 specimens from the Zao River section from one horizon (sample no. 

 24173). GSP BM 2519-20. 



Type locality. Rakhi Nala section. 



Type horizon. Upper Chocolate Clays, sample no. 3652. 



Description. Sexual dimorphism distinct ; the females are shorter than the 



H 



w 



o-39 



o-39 



o-39 



0-38 



o-37 



— 



