Dr. A, Gunther on a new Labyrinthibranchiate Fish. 211 
heliciform Vertigo and by a large Succinea, also taken by Mr. 
Blanford, who will probably describe them together with a large 
Helix allied to H. Bajadera, Pfr. 
Cheltenham, Feb. 5, 1864. 
XXIV.—Description of a Labyrinthibranchiate Fish from the Nile. 
By Dr. Abert GinrHeEr. 
A very fine collection of fishes made on the Upper Nile, 
at Chartoum and Gondokoro, by Consul John Petherick, con- 
tained, among other novelties, a species of Labyrinthibranchiate 
fish belonging to the genus Ctenopoma, Peters, species of which 
have hitherto been found only in Southern and Eastern Africa, 
where they represent the Hast-Indian Anabas. 
Ctenopoma Petherici. 
D. =, or ~, o>. A. co, G,tat. 29. UL. transy. = = 
The height of the body is one-third, or a little more than 
one-third, of the total length (without caudal) ; the maxillary 
extends to below, or but slightly beyond, the anterior margin of 
the eye. Teeth in the jaws and on the palate in narrow bands, 
. The diameter of the eye equals the extent of the snout. Five 
series of scales between the orbit and the angle of the pre- 
operculum, the outer series covering the preopercular margin. 
Operculum, inter-, and suboperculum strongly serrated. The 
soft rays of the vertical fins covered with small scales. Brownish 
olive; many scales with a brown central spot, these spots being 
less distinct in old specimens than in young ones; a round 
black spot, sometimes edged with whitish, on the root of the tail. 
The largest specimen is 63 inches long. 
This species is more nearly allied to C. multispine than to 
C. microlepidotum, but may be readily distinguished by its 
deeper body, by its narrower mouth, the maxillary extending to 
below the middle of the eye in C. multispine, &c. 
The same collection contained examples of Ophiocephalus 
obscurus, Gthr., described from West-African specimens, and a 
complete series of Clarotes, showing that this genus has been 
founded by Hyrtl and Kner on a deformed specimen, and that 
the species has been long ago named Pimelodus laticeps by 
Riippell, the development of the rays and of the spine of the 
adipous fin being dependent on age. 
