216 SILUEIDJS. 



Eleventh Group. RHINOGLANINA. 



Stenobranchiate Siluroids with the anterior and posterior nos- 

 trils close together. 



Central Africa ; Bengal. 



84. RHINOGLANIS. 



Two dorsal fins, both composed of rays, the first with a strong 

 spine ; anal rather short. Teeth in both jaws minute ; palate eden- 

 tulous ; mouth transverse, of moderate width, mandibles well deve- 

 loped. Barbels six, not compressed. Eyes free, of moderate size ; 

 the posterior nostril very large, open. Neck witb broad dermal bones. 

 Gill-openings rather narrow, not extending downwards beyond the 

 root of the pectoral. Ventrals with seven rays, inserted below the 

 posterior rays of the first dorsal fin. 



Upper Nile. 



I am obliged to establish this genus, on a single very small example. 

 Its most characteristic, feature would appear to be the presence of a 

 rayed dorsal fin where we should expect an adipose. However, 

 we must not forget that there are Siluroids in which an apparently 

 adipose fin has rays in its interior ; and consequently the question 

 arises whether this fin, in our fish also, may not change with age. It 

 is proved by other characters that Rhinoglanis is not the young of 

 any known Siluroid. The genus is somewhat allied to Synodontis, 

 but differs, besides the characters mentioned, in the structure of the 

 barbels, in the position of the ventrals, and apparently in the dentition. 



One might ask why this genus is not referred to the next sub- 

 family, with which it appears to agree in the position of the ventrals. 

 But, in fact, the real position of these fins is scarcely different from that 

 in the Synodontes, the dorsal fin extending a little more backwards 

 on the back, and having more rays than are found in the Doradina. 

 It is possible also that with age the ventral fins really take a more 

 backward position. Moreover, there is no trace of the reverted flap- 

 like lower Up which is so characteristic of the greater part of the 

 following subfamily. We may conclude, from analogy , that Rhino- 

 glanis has a large anterior vertebra. 



1. Rhinoglanis typns. 



D. g 1 9. A. 10. P. 1/6. V. 7. 



The head is nearly as broad as high, and its length is somewhat 

 more than the height of the body, two-ninths of the total (without 

 caudal) ; it is entirely osseous above, with a deep and broad longi- 

 tudinal groove on the forehead. The snout is obtusely rounded in 

 front, and rather longer than the diameter of the eye, which is two- 

 sevenths of the length of the head, and eqiial to the width of the 

 interorbital space. The maxillary barbel extends nearly to the origin 

 of the second dorsal ; the mandiluilary barbels are inserted close to 



