5. MICBOPTEEYX. 461 



c. Half-grown. Lake Champlain. Purchased of Mr. Frank. 



d. Adult. North America. Purchased of Mr. Warwick. 



e. Half-grown. New Orleans. Purchased of Mr. Cuming. 

 /. Adult. Cuba. Presented by the Zoological Society. 



g, h. Half-grown. S. Domingo. Purchased of Mr. Cuming. 

 ?"-m. Half-grown : skins. Jamaica. From Dr. Pamell's Collection. 

 n, 0. Half-grown : skins. West Indies. 



p. Adult : not good state. Bahia. Purchased of M. Parzudaki 

 q, r. Half-grown. Brazils. Presented by Lord Stuart. 

 s. Adult : skin. From Gronow's Collection. 

 t. Half-grown, Presented by the Zoological Society. 

 u, V. Half-grown. From the Haslar Collection. 

 w. Half-grown. Purchased of Mr. Frank. 

 x,y. Adult: bad state. Old Collection. 

 z. Adixlt. 



a. Half-grown: skeleton. Niger Expedition. From Mr. Eraser's 

 Collection. 



Sheleton. — The skull is rather compressed, and its upper suiface 

 is provided with five crests, the middle of which is strong, elevated, 

 with the upper angle roiinded, extending to the anterior extremity 

 of the frontal bones. The jaw-bones are rather feeble and trans- 

 parent. The praeoperculum has the interior ridge scarcely promi- 

 nent, and the muciferous channel appears to be very rudimentary ; 

 its inferior limb is shorter than the posterior, and the angle is 

 roimded. The operculum is somewhat narrow, with a slight pos- 

 terior notch ; the sub- and interoperculum are obliquely directed 

 upwards, and the latter is crescentic. The cavity formed by the 

 humerus and the radius is .oblong, quadrangular, the edges of the 

 two bones running in a parallel direction ; there is an ovate foramen 

 near the symphysis of the humeral bones. The pubic bones are 

 little developed and styliform. 



There are ten abdominal and fourteen caudal vertebrce, the length 

 of the former portion of the vertebral column being one-half of that 

 of the latter. The neural and haemal spines are strong, and the 

 three anterior hsemals have an interior channel, and are sometimes 

 united by bony cross-bars, like the processes of the ribs of birds. 

 Each of the five posterior abdominal vertebrae has a pair of inferior 

 apophyses at its anterior extremity, and another at its posterior ; the 

 apophyses of one side converge and are anchylosed together. The 

 ribs are slender, styliform. The intemeurals and interhaemals are 

 dilated and transparent. The first interhaemal is exceedingly strong, 

 firmly joined to the haemal of the first caudal vertebra, somewhat 

 concave anteriorly, and terminating in a dilated portion with an an- 

 terior and a posterior process ; this bone forms the base for the two 

 anal spines. The interhaemals of the first five anal rays als© rest 

 upon the first haemal ; the second haemal supports only two inter- 

 haemals, the third three, the fourth again two, the fifth again three, 

 &c. The base of the interhaemals, to which the anal rays are joined, is 

 swollen, and emits a small oblique process for each of the anal rays. 



