180 Jcmrnal of the Asiatic Society of Bengal. [April, 1910.] 



Amblypterus have already been described from the Khunmu 

 beds and they belong to the group of A. latus, and the present 

 specimen perhaps indicates the existence of a different form. 

 It is smaller than any of the specimens described by Dr. 

 Smith Woodward, and the general outline appears to be more 

 slender. 



The portion preserved measures about 78 mm. The trunk 

 is regularly fusiform and the dorsal contour seems to be per- 

 fectly straight. The maximum depth of the trunk is nearly 2-5 

 times as great as the width of the caudal pedicle which is about 

 three-quarters the length of the space between the termination 

 of the anal fin and the origin of the caudal fin. In the ex- 

 tremely anterior region there are some impressions which 

 represent some of the bones of the head, and among them may 

 be distinguished the clavicular impressions ornamented with 

 ridges, rather coarse and arranged more or less zonally. Of the 

 different fins the dorsal and the anal are the best preserved 

 ones ; and next to them are the caudal ; and only traces of the 

 pectoral and the pelvic ones are to be met with. The dorsal 

 and the anal fins are short-based : the former are somewhat in 

 advance of, and slightly less than, the latter in size. The inter- 

 space between the anal and the pelvic fins is less than that 

 between the pelvic and the pectoral ones. The articulated 

 segments of the fin-rays are longer than broad,. The scales are 

 a little longer than broad and are quite smooth : the upper and 

 lower margins show peg-and-socket structure. The course of 

 the lateral line is marked by a very prominent continuous ridge 

 on the inner surface of each scale through which it passes, this 

 being very prominent also on some of Dr. Smith Woodward's 

 specimens. 



genera Rhabdolepis , Troschel, and Elonichthys, Giebel, respectively. Dr. 

 Smith Woodward has, however, subsequently united these two genera 

 together with (?) Propalceoniscus , (?) Ganacrodus and Cosmoplychus, and 

 has retained Giebel's term (Catalogue of fossil fishes, pt. ii, p. 487). 



