GYMNALLABES.— CH ANN ALL ABES. 271 



Under the name of G. typus, forma heterocercalis, Lonnberg, Ofvers. 

 Vet.-Akad. Forh. Stockholm, 3895, p. 184, has noticed a fish from 

 Cameroon which differs from Gunther's description and figure in the 

 somewhat turned up caudal fin, giving it a heterocercal appearance, and 

 in having the pectoral spine serrated on both sides. 



5. CHANNALLABES. 



Giintb. Ann. & Mag. N. H. (4) xii. 1873, p. 143 ; Bouleng. Poiss. Bass. Congo, 

 p. 2G3 (1901), and Proc. Zool. Soc. 1907, p. 1094. 



Closely allied to the preceding, but still more degraded and eel- 

 shaped ; pectoral fin rudimentary or absent, ventral s absent. 

 Vertebra? 107. 

 A single species. 



1. CHANNALLABES APUS. 



Gymnallabes apus, Giinth. t. c. p. 142. 



Cliannallabes apus, Bouleng. 11. cc. pp. 264 and 1094, fig. 



Body extremely elongate and serpentiform ; length of head 10 

 to 14 times in total length. Head \\ to 1J times as long as broad ; 



occipital process acutely pointed ; a sole- 

 lg " " ' ^_ shaped frontal fontanelle ; an oval occipital 



fontanelle, partly on the occipital process ; 

 eye extremely small, nearly hidden under 

 the skin in the adult; band of prse- 

 maxillary teeth 3 times as long as broad ; 



^^^^^^^^^^^^ 



Channalktbes apus. 

 Type (P. Z. S. 1907). |. 



vomerine teeth pointed, forming a crescentic band which is a little 

 narrower ; nasal barbel | to § length of head ; maxillary barbel as 

 lon°- as head or slightly shorter; inner mandibular barbel a little 

 shorter than the nasal, outer mandibular a little shorter than the 



