270 



SILUKID^E. 



i. GYMNALLABES. 



Giinth. Ann. & Mag. N. H. (3) xx. 1867, p. Ill ; Bouleng. Proc. Zool. Soc. 1907, 

 p. 1093. 



Degraded, anguilliform Clarias, with the sides of the head unpro- 

 tected by bone, even the postorbital shield being absent, the pectoral 

 and ventral fins very small, no free border to the eye, and the dorsal and 

 anal completely united with the caudal. 



A single species. 



1. GYMNALLABES TYPUS. 

 Giinth. 1. c. pi. ii. fig. A ; Bouleng. 1. c. 



Depth of body 14 to 15 times in total length, length of head 1\ to 8^ 

 times. Head about \\ times as long as broad, the width of the bony 

 part, in the middle, \ to \ width of head ; occipital process acutely 

 pointed ; eye very small ; interorbital width less than width of mouth, 

 about f length of head ; band of prsemaxillary teeth 3 to 3J times as 

 long as broad ; vomerine teeth pointed, forming a crescentic band which 

 is narrower than the praemaxillary band ; a much developed lobe at the 

 angle of the mouth ; nasal barbel f- to |- length of head ; maxillary- 



Pig. 224. 



Gymnailabes tijpus. 

 Type, after Giinther (I. c). 



i 



Dorsal 98-110, 



barbel a little longer than head ; inner mandibular 



barbel § to £ length of head, outer a little shorter 



than head. Gill-rakers moderately long, 10 on 



anterior arch. Clavicles hidden under the skin. 



its distance from occipital process f to f length of head. Anal 82-88. 



Dorsal and anal completely united with caudal, which is § to £ length 



of head. Pectoral \ to f length of head, with a very short smooth 



spine. Ventral 2 to 2^ times as distant from root of caudal as from end 



of snout. Uniform blackish brown, lighter brown on the belly. 



Total length 230 millim. 



Lower Niger and Old Calabar. 

 1-2. Types. Old Calabar. 



3. Ad. Ossomari, S. Nigeria. Dr. W. J. Ansorge (C). 



