484 



FISHES 



lower lobe of the caudal. The fin -rays which support the 

 ventral portion of the caudal fin are more numerous and longer 

 than those in relation with the dorsal lobe, and hence at this 

 stage the tail is really heterocercal. 



T?ia. 281. — Larva of Polypterus senegalus. x 4. Showing its characteristio attitude 

 when resting on the bottom of an aquarium, and the large size of the cutaneous 

 gills. (Prom Budgett.) 



In the genus CalamicMhys the body is greatly elongate and 

 Eel-like in shape. Pelvic fins are absent, and normally there is 

 no suboperculum. The dorsal finlets are more isolated than in 

 Polyipterus, and each spine supports but a single soft ray. Only 

 a single species is known, C. calaharicus'^ (Fig. 282). 



Fig. 2i2.—Calamichthys calaiaricus. x |. (From a specimen in the Cambridge 

 University Museum.) 



Calamichthys has a more restricted distribution than Poly- 

 pterus, and is confined to certain rivers of West Africa. First 

 obtained at Creek Town on the Old Calabar river, it is now 

 known to occur in the delta of the Niger, on the coast of 

 Cameroon, and as far south as the river Chiloango, frequenting 

 the smaller muddy rivers opening into the estuaries.^ It is a 



^ Traquair, Journ. Geol. Soc. Ireland (2), 1871, p. 249. 

 '^ Boulenger, Les Poissons du Bassin du Congo, Bruxelles, 1901, p. 27. 



