124 Mr. G. A. Boulenger on Hymenochirus. 



Fronto-parietals fused to a single bone. 



Single ostium phavyngium. 



No distinct mento-meckelians. 



Sacral diapophyses extremely dilated and fused with the 

 urostyle. 



Vertebra? opistliocoelous. 

 Clifiracters in common with Pipa : — 



Fusion of tlie first and second vertebrfR. 



Coracoids much expanded towards the sternal end. 



Very strong wing-like expansion of the ilia. 

 Characters in common with Xenopus : — 



Sternal cartilage not embraced by, extending outwards 

 beyond, the epicoracoid cartilages. 



Long thyrohyals. 

 Hymenochirus stands by itself in the presence of only 5 

 prsesacral vertebrse ; the second and third diapophyses are 

 very long and subequal, but not so long and not so strongly 

 directed forwards as in Pipa and Xenopus ; the first, fourth, 

 and fifth are shorter and also subequal. Fronto-parietal 

 very broad, measuring half the width of the skull. Thyro- 

 hyals extremely long. Tibio-fibula with a wing-like ex- 

 pansion of tliin bone on eacli side, forming a deep groove on 

 the outer side; the two bones of the tarsus united by similar 

 bony expansion, which projects wing-like on each side. 

 PehJytes \\ as so far the only Batrachian in which a fusion 

 of the astragalus with the calcaneum was known to occur, 

 and this in a very different manner. The praecoracoids are 

 feebly curved and form a nearly straight transverse bar, 

 instead of an angle directed forwards. 



Having thus indicated the most salient osteological features 

 of IJyinenochirus Boettgeri, I pass on to a description of the 

 external characters. 



Head small, very strongly flattened, a little broader than 

 long; snout rounded, projecting slightly beyond the mouth ; 

 nostrils terminal, directed upwards and forwards; eyes small, 

 without lids, supero-lateral ; pupil round; interorbital space 

 about half the width of the head; no tympainim. Body 

 much depressed, twice and one third {^) to thrice (?) as 

 long as the head. Fore limb rather feeble ; fingers moderately 

 elongate, sharply pointed, one-haU or two-thirds webbed, first 

 a little shorter than second, third hingcst; no carfial or sub- 

 articular tubercles. Hind limb strong; til)io-tarsal articu- 

 lation reaching the eye or between the shoulder and the eye; 

 tibia two fifths to one half length of head and body ; toes 

 broadly webbed, but not to the tips, which are sharply 

 pointed, the inner three armed with a small black claw j third 



