51 



Genus Hopladelus (Raf.) Gill. 



SYNONTMY. 



Sllurus sp. Raf. American Monthly Magazine and Critical Review, 



vol. III. p. 355. 

 Glanis sp. JRcif. Mass. Monthly Magazine and Critical Review, 



vol. III. p. 447, vol. IV. p. 107. 

 Pimelodus sp. Raf. Ichthyologia Ohiensis. 

 . Ictalurus sp. Raf. Ichthyologia Ohiensis. 

 Leptops Raf. Ichthyologia Ohiensis, p. 64. 

 Opladelus Raf Ichthyologia Ohiensis, p. 64. 

 Ilictis Raf Ichthyologia Ohiensis, p. 66. 

 Pylodictis Raf. Ichthyologia Ohiensis, p. 67. 

 Pimelodus sp. Lesueur, Kirtland, Val, &c. 



Body elongated and anteriorly depressed. Head depressed and 

 oblong, covered with a thick skin. Supraoccipital bone, posteriorly 

 free. Mouth wide. Lower jaw longest. Branchiostegal membrane 

 with twelve rays on each side. Anterior dorsal fin with its spine 

 enveloped in the skin. Adipose fin short and thick. Caudal fin 

 slightly emarginated. Caudal peduncle posteriorly, equally convex. 

 Ventral fins with nine rays (1.8). 



Type Hopladelus olivaris Gill. 



Syn. Silurus olivaris Raf. 



Genus Olyra McClelland. 



SYNONYMY. 



Olyra McClelland, Calcutta Journal of Natural History, vol. ii. p. 

 576. 



Body elongated and subcylindrical. Head depressed, especially at 

 the snout, and moderately elongated, covered with a thick skin. The 

 supraoccipital bone apparently free posteriorly. Mouth moderately 

 wide ; jaws of equal length. Branchiostegal membrane with about 

 six rays on each side. Anterior dorsal with no stout spine. Anal 

 fin long, with more than twenty rays. Caudal fin lanceolated, in- 

 serted on the symmetrical termination of its peduncle. Ventral fins 

 with five rays. 



The genus Olyra as here restricted, includes only the first species 

 of M'Clelland's genus which he has called Olyra longicaudaius. The 

 small number of branchiostegal and ventral rays is one of the most 

 distinguishing characters of that genus. Dr. M'Clelland may have 

 erred in the exact number, as he was often inaccurate, but the true 

 number must be very near that given. The small simple ray of the 

 ventral fin may possibly have been omitted, but for the present, we 

 are compelled to rely on the accuracy of the describer of the specie 



Type Olyra longicaudata Mc Clelland. 



