324 REV. S. GRAHAM BIRKS 



two sizes, the larger ones being internal to the smaller and 

 occurring at intervals of about seven teeth. 



Oval patches of vomerine teeth have been recorded as 

 present close to the middle line on each side of the fore part 

 of the palate. A large patch of minute clustered teeth is 

 disposed in a long, narrow and posterior median strip. The 

 dentition is that of a predatory fish. 



The paired fins are obtusely lobate and are accompanied 

 by basal scales or fulcra. Between the ventrals several large 

 pelvic scales are interposed. Possibly they vary according to 

 sex. There are two dorsals, the first nearly opposite the 

 ventrals, the second nearly opposite the anal fin. The anal 

 fin is close to the root of the tail. The caudal fin is inter- 

 mediate between the heterocercal and diphycercal types ; it is 

 rhomboidal and oblique, projecting further above than below. 

 Rays arise from both the upper and the lower margins of the 

 body-continuation, but those of the lower side commence in 

 advance of those of the upper. All the fins are composed of 

 numerous closely set rays, divided by very close transverse 

 articulations, except quite at their proximal extremities, which 

 are covered by the scales of the body ; they dichotomise to- 

 wards their extremities, and their free surfaces are brilliantly 

 ganoid and punctated like the scales. 



The centra and the neural and haemal arches of the vertebra? 

 are all thoroughly ossified ; the centra are in the form of rings. 

 They are relatively broad in this species. 



The length of a large member of this species may have 

 amounted to four or five feet. 



It seems probable that the so-called M. pygmaus is the 

 young of M. hibberti. 



