OF FISHES FEOM LAKE TANGANYIKA. 23 



I. Vent nearly equally distant from the end of the snout and the base of the caudal fin. 



A. Two strong prseopercular spines. 



D. XXIII-XXIV 75 ; A. II 75-76 j length of head (measured to extremity of opercle and without 

 rostral appendage) hardly twice in its distance from vent and 6 times as great as its 

 distance from the first dorsal spine 1. M. mai-chii Sanv. 



D. XXIV 100 ; A. II 100 ; length of head 3i times in its distance from vent, equal to its distance 

 from the first dorsal spine 2. M. cnjptacanthus Gthr. 



D. XXVII 85 ; A. Ill 92 ; length of head 2| in its distance from vent^ 3 times as great as its 

 distance from first dorsal spine 3. M. congicus Blgr.' 



D. XXVI-XXX 80; A. II 80 4<. M. liber iensis'Blgv.'' 



D. XXIX-XXX 117-130; A. II 117-127; length of head nearly 4 times in its distance from 

 ventj and nearly twice as great as its distance from the first dorsal spine. 



5. M. loennbergii Blgr.' 



B. Prseopercular spines minute (young) or absent. 



D. XXVII-XXVIII 70-80 ; A. II 80-90 ; length of head 3 to 4 times in its distance from vent, 

 equal to or a little less than its distance from the first dorsal spine. 



6. M. flavomarginatus Blgr." 

 D. XXVII 80-82 ; A. II 60-65 ; length of head equal to its distance from the first dorsal spine. 



7. M. niger Sauv. 



D. XXVII-XXIX 65-70 ; A. II 68-75 ; length of head 2\ to 3 times in its distance from the 

 ventj and \ in its distance from the first dorsal spine ... 8. M. shiranus Gthr. 



D. XXIX 95 ; A. II 85 ; length of head 3 times in its distance from the vent, and ^ in its distance 

 from the first dorsal spine 9. M. nigromarginatus Blgr." 



D. XXV-XXVII 70-80 ; A. II 70-80 ; length of head twice in its distance from the vent, and 

 nearly ^ in its distance from the first dorsal spine .... 10. M. tnoorii Blgr. 



II. Vent much nearer the caudal fin than the end of the snout ; one or two prseopercular 



spines. 



D. XXX 85 ; A. II 70 11. M. marmoratus 'Perugia..'' 



D. XXXIII-XXXV 50-60 ; A. II 50-60 12. M. tanganiccB Gthr. 



III. Vent much nearer the end of the snout than the caudal fin. 



D. XXXI-XXXII 103 ; A. I 116 \Q. M. ophidium Gthr. 



^ A species from the Upper Congo founded on a single specimen with mutilated tail and regenerated caudal 

 fin. I have now a perfect specimen. 

 ^ M. marchii Steind. nee Sauv. — Liberia. 

 '' M. cryptaeanthus Loennberg nee, Gthr. — Cameroon. 



* A new species founded on specimens from the Gaboon previously referred to M. cryptacanthus. 

 ' A new species founded on a single specimen from Ashantee. 



* Type examined. Vent equally distant from the bead and from the caudal ; head once and a ball fts lobg 



as its distance from the first dorsal spine ; 17 scales between origin of soft dorsal and lateral line. 



