5. MICEOPTKRVX. 461 



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



d. Adnlt. North America. Pm'chased 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. Cimiing. 

 i-^n. 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-groAvn. Brazils. Presented by Lord Stuart. 

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

 t. Half-growm. Presented by the Zoological Society. 

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

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

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

 z. Adult. 



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

 Collection. 



Sl-ehton.— The skull is rather compressed, and its upper surface 

 is provided ■\\'ith five crests, the middle of which is strong, elevated, 

 with the upper angle rounded, extending to the anterior extremity 

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

 parent. The pra3operculum has the interior ridge scarcely promi- 

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

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

 rounded. The operculum is somewhat naiTow, 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 sjTuphysis of the humeral bones. The pubic bones are 

 little developed and styliform. 



There are ten abdominal and fomieen caudal vertebrce, the length 

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

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

 three anterior hfemals 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 anteiior extremity, and another at its posterior ; the 

 apophyses of one side converge and are anehylosed together. The 

 ribs are slender, styliform. The intern eurals and interhiemals are 

 dilated and transparent. The first interhsemal is exceedingly strong, 

 firmly joined to the ha-mal of the fii'st caudal vertebra, somewhat 

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

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

 anal spines. The interhaeraals of the first five anal rays also rest 

 upon the first hsemal ; the second ha3mal supports only two inter- 

 haemals, the tliii'd three, the fom-th again two, the fifth again three, 

 &c. The base of the interhacmals, to which the anal raj's are joined, is 

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



