356 On Belonorhynclms and Amblyuru?. 



that in Belonorhynchus the notochord was persistent. Kner * 

 suspected that there were complete vertebral centra in the 

 anterior portion of the trunk and small triangular calcifica- 

 tions in the sheath of the notochord more posteriorly ; but the 

 small bodies must doubtless be regarded as the expanded 

 proximal portions of the neural and hsemal arches, quite 

 similar to those of many other early Ganoids. It may be 

 added, moreover, that Bronn's description of the fin-rays as 

 transversely jointed is correct, though subsequently questioned 

 by Kner, the fossils being often deceptive owing to the cir- 

 cumstances of preservation. 



With regard to the systematic position of the genus, Kner 

 institutes many comparisons with the living Fistularia, and 

 Liitken f has suggested that it is probably related to the 

 Cretaceous Dercetis. The characters of the skull, however, 

 together with the disposition of the fins and the primitive 

 nature of the vertebral axis, appear to indicate much more 

 affinity with Belonostomiis and its allies, as originally recog- 

 nized by Bronn ; and the genus may therefore be referred to 

 a nearly related family, the Belonorhynchidee, characterized 

 as follows : — Body long and slender ; snout much elongated 

 and pointed, Notochord persistent, the bases of the arches 

 expanded. Paired fins moderately developed ; dorsal and 

 anal fins lai'ge, nearly equal and opposite, very remote ; 

 caudal symmetrical; fulcra minute or absent. No continuous 

 squamation, but a median longitudinal series of dorsal and 

 ventral scutes, and a single lateral series on each side support- 

 ing the lateral line. 



II. Amblyukus, Agassiz. 



While referring to Liassic Ganoids it may be well to })lace 

 on record a correction which was made some years ago by 

 Mr. William Davies in the British Museum, but does not 

 appear to have been hitherto published. Whatever be the 

 nature of the head-fragment associated by Agassiz with the 

 genus Aniblyurusj there can be no doubt that the type speci- 

 mens of the single species, Amhlyurus niac7'ostonius \, are 

 really vertically crushed specimens of Dajpedius ; and the 

 name thus falls into the synonymy of this well-known Lower 

 Liassic fish. 



* R. Kner, loc. cit. p. 192, pi. vi. tigs, b, c, 



t C. F. Liitken, '' Professor Kner's Classification of the Ganoids," 

 Geol. Mag. vol. v. (1868), p. 432. 

 1 L. Agassiz, torn. cit. pt. 1, p. 220, pi. xxt e. 



