266 



SILUEID^. 



2. ALLABENCHELYS. 



Bouleng. Proc. Zool. Soc. 1902, i. p. 234, and 1907, p. 1091. 



Characters of Clarices, but casque less developed, the sides of the 

 head naked, only the postorbital shield being present. Dorsal and anal 

 reaching caudal. Vertebrae 68-70. 



Two species : — 



Depth of body 7-8^ times, head 5-5^ times in total 



length ; ventrals 1^-lf as distant from root of 



caudal as from end of snout ; D. 65-75, A. 60-65. 1. A. brevior, p. 266. 

 Depth of body 9-12 times, head 5^-6 times in total 



length j ventrals 1^-2 as distant from root of 



caudal as from end of snout; D. 80-90, A. 60-75. 2. A. longicauda, p. 267. 



1. ALLABENCHELYS BREVIOR. 

 Bouleng. Ann. & Mag. N. H. (7) xii. 1903, p. 439, and Proc. Zool. Soc. 1907, 

 p. 1091, fig. 

 Depth of body 7 to 8% times in total length, length of head 5 to 5^ 

 times. Head 1|- to 1^ times as long as broad, smooth above, the bony 

 casque, in the middle of the head, about \ width of head ; postorbital 

 bone narrow ; occipital process acutely pointed ; a small frontal 

 fontanelle ; occipital fontanelle a little smaller, partly on occipital 



process ; eye very small, 2\ to 3 times 

 in length of snout, 5 to 6 times in inter- 

 orbital width, which is § length of head ; 

 band of prsemaxillary teeth 3 to 4 times as 

 long as broad; vomerine teeth conical 

 or subgranular, forming a crescentic 

 band which is as broad as or a little 



Fig. 221. 



Allabencheh/s brevior. 

 Type (P. Z. S. 1907). § '. 



| to § length of 



broader than the prasmaxillary band; nasal barbel 



head ; maxillary barbel as long as or a little shorter than head, not 



reaching beyond middle of pectoral fin ; outer mandibular barbel § to ^ 



