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On new African Fishes. G37 



LXIX. — Descriptions of Four new African Fishes of the 

 Genus Mastacembelus. Bj G. A. Boulenger, F.R.S. 



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



Mastacembelus batesii. 



Depth of body 15 to 16 times in total lengthy length of 

 head 8 to 9 times. Vent equally distant from end of snout 

 and from caudal, its distance from head 3 to 3^ times length 

 of latter. Snout 3 to 4 times as long as eye, ending in au 

 appendage which is a little longer than eye; mouth extending 

 to below anterior third or centre of eye; no prreorbital or 

 pr?eopercular spines. Dorsal XXX-XXXIII 80-90 ; spines 

 extremely short, last scarcely longer than eye ; distance be- 

 tween first spine and head f to | length of head. Anal II 

 80—90. Caudal rounded-subacuminate. Scales very small, 

 16-18 between origin of soft dorsal and lateral line; latter 

 formed of a few tubules widely separated from one another. 

 Brown or olive above, with dark spots or marblings and a 

 vertebral series of small black spots ; a regular series of 

 round or squarish dark brown spots on each side of the back, 

 sometimes confluent into a wavy band ; yellowish on tiie 

 sides, with a more or less distinct brown network ; dorsal 

 and anal fins spotted with brown. 



Total length 320 mm. 



Several specimens, from the Ja River at Bitye, South 

 Cameroon (Congo Basin), were sent to the Natural History 

 Museum by Mr. G. L. Bates. 



Mastacembelus ubangensis. 



Depth of body 15 to 10 times in total length, length of 

 head 7 times. Vent equally distant from head and from 

 caudal, its distance from head 3 times length of latter. 

 Snout twice as long as eye, ending in an appendage which is 

 hardly as long as eye; mouth extending to below anterior 

 border of eye; a strong erectile spine below nostril ; two 

 strong prteopercular spines. Dorsal XXIX-XXX 110 ; 

 distance between first spine and head | length of latter. 

 Anal II 110. Caudal pointed. Pectoral \ length of head. 

 Scales very small, about 15 between origin of soft dorsal and 

 lateral line. Brownish, with an ill-defined darker band along 

 the side of the head and body; vertical fins whitish, with a 

 series of large black spots at the base of the posterior part of 

 the dorsal ; a black spot on the caudal. 



