BY J. DOUGLAS OGILBY. 608 



tudinal axis of the body. The eye is much smaller, being 

 (according to the figure) about one-third of the length of the 

 head ; now if the two fishes belonged to the same species we 

 would expect this character to be reversed, the rule being tliat 

 the younger a fish is the larger the eye is proportionately; it is 

 also situated midway between the upper and lower profiles of the 

 head and much more forward, the cleft of the mouth and the 

 whole of the maxillary being below the level of the eye, and the 

 latter extending backwards to the vertical from its posterior 

 border, whereas in our species the cleft of the mouth is on the 

 same le^el with the inferior edge of the eye and the maxillary is 

 wholly in front and only partially below it. 



The similarity in the number of dorsal rays is sure to attract 

 attention, but the comparative height of the second dorsal is not 

 nearly so great and there is a more pronounced disproportion 

 between the strength of the rays in the two dorsals, so much so 

 as to make me somewhat sceptical as to whether the rays of the 

 first dorsal ever were much produced in the Newcastle specimen. 

 The origin of the first dorsal in arawatce is considerably further 

 forward, .but this is doubtless in some measure owing to the much 

 greater verticality of the profile and the anterior position of the 

 nuchal crest. Clarke lays considerable stress on the presence of 

 a pair of cutaneous lobes bordering the caudal peduncle above 

 and below, which he views in the light of adipose dorsal and anal 

 fins, but these are merely membranous expansions of the skin due 

 to immaturity and would assuredly not have been noticeable 

 except in the case of such a perfect example as its describer was 

 fortunate enough to possess; they are of no specific value. 



The first ventral ray in arawatce is spoken of and figured as a 

 spine (V. 1+5) and is serrated, in which characters it differs 

 from our fish. 



The upper lobe of the caudal fin is inserted almost at right 

 angles to the vertebral axis and the outer rays are serrated 

 externally throughout their entire length, while there is a con- 

 spicuous lower lobe consisting of six rays on the same plane as 



