2i 4 THE TANGANYIKA PROBLEM. 



MASTACEMBELID/E. 



86. Mastacembelus frenatus. — Blgr. 1901. (Fig. p. 215. Upper.) 



Depth of body 13 times in total length, length of head 8| times. Vent equally 

 distant from end of snout and from caudal fin, separated from head by a space equal 

 to 3§ times length of latter. Snout 3 times length of eye, produced into a trifid 

 appendage, the length of which exceeds a little diameter of eye ; buccal 

 cleft extending to below anterior border of eye ; no prreopercular spines. 

 Dorsal and anal confluent with caudal, which is short and rounded ; 

 dorsal XVIII. 85; anal 11-90; first spine very short, second \ length of head; 

 distance between first dorsal spine and head i§ times length of latter. Pectoral £ 

 length of head. Scales extremely small, 22 between origin of dorsal and lateral 

 line. Yellowish brown above, marbled with darker, yellowish beneath ; a dark 

 brown streak on each side of the head, passing through the eye ; two brown bars 

 across the caudal. 



Total length, 250 millim. 



Described from a single specimen, a female full of ova from the north end of 

 Lake Tanganyika. 



87. Mastacembelus moorii. — Blgr. 1898. (Fig. p. 215. Lower.) 



Depth of body 14 times in total length, length of head (without rostral appendage) 

 6^ times ; vent equally distant from end of snout and base of caudal ; length of 

 head 2k to 3 times in its distance from vent, and ^ in its distance from first dorsal 

 spine. Snout 3 times as long as eye, ending in a trifid dermal appendage which 

 is a little longer than eye ; cleft of mouth extending to below centre of eye ; no 

 prs-opercular spines. Vertical fins united with the rounded caudal. Dorsal XXV.- 

 XXVII. 70-80 ; spines very short. Anal II. 70-80. Pectoral J length of head. 

 Scales very small, 30-35 between origin of soft dorsal and lateral line. Brown, tail 

 with a wide-meshed blackish network ; dorsal and anal whitish ; with a vertical 

 series of blackish spots or vertical bars ; anal and caudal edged with blackish. 



Total length, 440 millim. 



Described from two specimens from Mbity Rocks. 



This species has been compared with M. marmoratiis, Perugia, from the Congo, 

 which differs in the more slender body (its depth contained 20 times in the total 

 length) with larger scales, the shorter tail, the longer rostral appendage (measuring 

 twice the diameter of the eye), and the higher number (30) of dorsal spines. 



88. Mastacembelus ellipsifer. — Blgr. 1899. 



89. Mastacembelus tanganioe. — Ghrt. 1893. 



