452 Dr. A. Giinther on the Ichthyology of West Africa. 



1103. Perisporium vulgare, Corda, fasc. 2. fig. 97. 

 On old rope. Batheaston, Nov. 1864. 



Sporidia in chains of four, -00025 inch long when separated; 

 ascijvith a delicate stem. 



[To be continued.] 



XLVIII. — A Contribution to the Ichthyology of West Africa. 

 By Dr. Albert Gunther. 



The British Museum has lately received a small collection of 

 West-African fishes, a part of which deserve some attention, 

 inasmuch as they appear to be undescribed, or at least new to 

 that fauna. We do not know the exact locality where these 

 specimens have been obtained, but it is probable that they are 

 from the Niger. The collection contained, besides other well- 

 known West-African species, large examples of Lates* niloticus, 

 Clarotes laticeps, and Citharinus latus, which had been known 

 hitherto from the Nile only; also Distichodus rostratus and 

 Alestes macrolepidotus, and, finally, the common Indian Drepane 

 punctata. 



The following are new : — 



Synodontis guttatus-f. 



D. 1/7. A. 12. P. 1/10. V. 8. 



The gill-opening extends downwards to before the root of the 

 pectoral fin. Mandibular teeth shorter than the eye, about 

 thirty in number. Maxillary barbels about as long as the head, 

 not fringed; mandibular barbels provided with filaments, the 

 outer ones much shorter than the head. The length of the 

 head is rather less than two-sevenths of the total length (without 

 caudal). Nuchal carapace not much arched, longer than broad; 

 its posterior processes extend somewhat behind the dorsal spines. 

 Dorsal spine a little longer than that of the pectoral fin, but 

 shorter than the head ; both these spines smooth in front. Hu- 

 meral process nearly twice as long as high, pointed behind. 

 The distance between the dorsal and adipose fins equals the 

 length of the latter, which is nearly as long as the head. Body 



* The genus Lates has been described as being without pseudobranchise. 

 However, it may be seen in large specimens that these organs are present, 

 although the fringes are extremely short and may be easily overlooked ; 

 they are well developed in Lates colonornm. 



t I take this opportunity of directing attention to the misplacement of 

 the heading " B. Mandibular teeth not longer than the eye," in p. 212 of 

 the 5th vol. of the Catalogue of Fishes. It should stand before "3. Syno- 

 dontis serratus," instead of before " 4. Synodontis schal," as indeed is 

 evident from the remarks made on these two species in p. 210. 



