On new Eels fro7n West Africa. 323 



XLII. — Description of Tioo new Eels from West Africa, 

 belonging to a new Genus and Familij. By C. Tate 

 Kegan, M.A. 



(Published by permission of the Trustees of the British Museum.) 



Heterenchelys, gen. nov. 



Naked, elongate, subcylindrical, witli the tail much longer 

 than the trunk. Dorsal and anal fins long, but very low 

 except towards the end of the tail, where they are confluent 

 \vith the caudal ; rays concealed beneath the skin ; no 

 pectorals. Gill-openings separate, placed low. Nostrils 

 lateral, the posterior in front of the very small eye. Mouth 

 moderate; teeth conical, biserial in jaws and on vomer; 

 tongue not free ; pharyngeal apertures of branchial clefts 

 wide ; pharyngeals covered with small teeth. 



Very similar to Moringua, which has the trunk much 

 longer than the tail, the teeth uniserial, and the pharyngeal 

 apertures of the interbranchial clefts small. A study of the 

 anatomy confirms the relationship to Moringua, but reveals 

 some important differences, notably that the heart is placed 

 just behind the gills and the palato-pterygoid is well developed 

 in Heterenchelys, whereas in Moringua the heart is a con- 

 siderable distance behind the gills and the palato-pterygoid 

 is vestigial. In these and other characters the wqw genus is 

 the more generalized ; it is the type of a new family, which 

 will be further characterized in a forthcoming paper on the 

 classification of the Apodes. 



Heterenchelys microphthalmus , sp. n. 



Depth about 22 in the length. Tail nearly twice as long 

 as rest of fish ; head, to gill-opening, about ^ as long as 

 distance from gill-opening to vent. Eye nearly equidistant 

 from end of snout and angle of mouth ; cleft of mouth a little 

 more than ^ the length of head. Coloration uniform. 



Two specimens, 390 and 460 mm. in total length, from 

 the mouth of the Congo, presented to the British Museum in 

 1893 by Mr. V. H. Cornish. 



Heterenchelys macrurus, sp. n. 



Depth about 27 in the length. Tail more than three times 

 as long as rest of fish ; head, to gill-opening, nearly f of 



