DICYNODONTID^. 



41 



Ptychosiagum orientale (Huxley 1 ). 



Syn. Dicynodon orientalis, Huxley 2 . 



Ptychognathus orientalis, Lydekker 3 . 



Imperfectly known ; of the approximate size of P. declive. This 

 species was founded upon fragments of the skull and teeth, and 

 imperfect bones of the limbs. The undermentioned specimen of the 

 occipital region, which agrees in relative size with the larger limb- 

 bones, and therefore probably belongs to the same species, affords the 

 grounds of the generic reference. 



The bones of the pectoral and pelvic girdles (figs. 9, 10) were at 

 first incorrectly determined, and are redescribed by the writer in 

 a paper published in the * Rec. Geol. Surv. Ind.' vol. xxiii. pt. i. 

 (1890). The difference in the size of the bones of the limb-girdles 

 and limbs may be merely sexual or individual. 



Hah. India. 



Kg. 8- 



Ptychosiagum orientale. —The occiput, restored; from the Panchet group of 

 Bengal. \. bo, basioccipital ; eo, exoccipital ; c, tubercle at junction of 

 exoccipital with supraoccipital ; a, b, descending processes; the imperfect 

 bone above the bar over the foramen magnum is the interparietal. (From 

 the ' Bee. Geol. Surv. Ind.') 



1 Paljeontologia Indica (Mem. Geol. Surv. Ind.), ser. 4, vol. i. pt. i. p. 8 

 (1865). — Dicynodon. 2 Loc. cit. 



3 Eec. Geol. Surv. Ind. vol. xx. p. 68 (1887), 



