1867. J MR. J. Y. JOHNSON ON A NEW SHARK. "13 



to any part of its surface is visible ; and it is the same with the 

 Juropean species, according to the observations of Eschricht and 

 Keinhardt. 



The hyoid bone is of the same form as that figured in Cuvier's 

 Ossem. Foss. vol. ,. pi. 25. f 13, being only so.nevvhat larger in the 

 middle, where the two cornua hyoidea are attached. The transverse 

 diameter is 20 inches, and the longitudinal in the middle of one of 

 the two points /inches. The cornua have a more curved form than 

 that figured by Cuvier, and are 12 inches lono-. 



Finally I should mention, what I omitted before, that in the era 

 mum IS a distinct lachrymal bone on eacli side in the prolongation 

 of the orb.t at the tore end, like that in Cuvier's figures (pi. 26) to 

 which IS attached the zygomatic bone, as Cuvier fi|ures the Rornual 

 of the Cape ot Good Hope (fig. 1 of the same plate). The tvmnanic 

 bone IS persistent and firmly united with the cranium ; and the vomer 



vided at the fore end by a longitudinal fissure into two parallel lob-^s 

 ^2 inches m length. 



6. Description of a New Genus of Spinacidce, fountbd upon 

 a Shark obtained at Madeira. By James Yate Johxson 

 C.M.Z.S. 



The Shark which forms the subject of the present com.nunication 



IS closely a hed to those members of the familv Spinaddce which 



constitute the genus CW,/.o^./i„;.«.; but since it' possesses a n.esial 



ooth in the lower jaw it cannot be assigned to that genus, and I 



therefore propose to found upon it a new genus named 



Machephilus. 



Body elongate, prismatico-triangular in section; head depressed 

 not distinct from the body ; nostrils on the inferior side of the head 



of he lit <? TirT '\' 7'' 'u^f''^' S--^^^'^ '' '^'^ commissure 

 Jnrt^ ' Scutella (scales) stalked. Two dorsal fins, each sup- 

 ported by a strong spine. No anal fin. The teeth of different form 

 HI the two jaws; those of the upper jaw consisting of t.iaJn a 

 cusps on subquadrate bases; those of the lower jaw compS of 

 cusps on subquadrate bases, the cusps being more and more^inc med 

 backwards as the teeth approach the back" of tha mouth, thus p e- 



nnr "iS Tf 'T''''^ '^^^^^ ^^ "^'"'^^ *«°th, consisdng of an 

 upright equilateral cusp on a quadrate base, in the lower ja^^^ 



Machephilus dumerilli, S ■ 



Of a uniform brownish-grey colour. Head rather broad, depressed 

 Proc. Zool. Soc — 1807, No. XLVI. 



