of the Genus Pellonula Sfc. " 20'3. 



2. Microthrissa royanxi. 



Microthn'ssa royav.vi, Bonlfner. Ann. Miis. Congo, ii. 1902, p. 2Ci, and 

 Ciit. Air. Fish. i. p. 161, tig.''l29 (1909). 



De[)tli of body 3-3^ in tlie lengtli, length o£ head 4. 

 Snout shorter than diameter of eye, wliicb is 3 in length of 

 head; jaws equal anteriorly; maxillary with minute teeth, 

 extending to below anterior niaigin of eye ; 14 gili-rakers on 

 lower part of anterior arch. 38 to 40 scales in a lonoituilinal 

 .«erieSj 12 in a transverse series; ventral scutes 12-13+6-7. 

 D')r:-;ai 13 ; origin equidistant from end of siiout and 

 base of caudal, behind the 8-iayed pelvics. Anal 23 (-25), 

 exteiKh'ng forward nearly to below end of do;-sal. (Jaudal 

 peduncle a little deeper than long. 39 vertebrse. 



fli.anghi 11. 



One of the types, 55 mm. in total length, from Bauzyville. 



4. POTAMOTHRISSA, gen. uov. 



Closely related to Pdlonula, but maxillary narrow, snpia- 

 inaxillary bone quite small, and no teeth on tongue or on 

 niaxiihiry. Dorsal fin of 13 or 14 rays, placed well forward, 

 its origin nuudi nearer to end of snout than to base of caudal, 

 above or in advance of first ray of privies ; anal of 17 or 18 

 rays, far b. hind dorsal. Scales 40-44/10. Yertebrse 42. 



1. Potamothrissa obtusiroNtris. (Fig. \,2.) 



Pellomda ohtiisirostris, Bouleng. Cat. Afr. Fish, i, p. 1.58, fig. 126 

 (1909). 



Jaws equal anteriorly. IG glll-rakei-s on lower part of 

 anterior arch. Ventral scutes 9-10+ 9-10. 

 Aruwinii River, Congo. 

 Two specimens, 72 mm. in total length. 



2. Potamothrissa acutirostris. 

 PeUunula acutirostris, Bouleng. Cat. Afr. Fish. i. p. 159, fig. 127 (1909). 



Lower jaw shorter than upper. 19 gill-ral<ers on lower 

 part of anterior arch. Ventral scutes 12-13 + 10-12. 

 Upper Congo. 

 Five specimens, uj) to 75 mm. in total length. 



5. Cynotiirissa, gen. no v. 



Differs from Pellomda in the very prominent lower jaw 

 and in the presence of an inner series of pnemaxillary teeth, 



