MARCUSENIUS. 



I / 



37-40. Ad., hgr., & yg. Between Luxor and Assuan. 



47. Ad. Assuan. 



48. Hgr. Lake No, White Nile. 



49. Hgr. Gondokoro, Bahr-el-Gebel. 



L. Loat, Esq. (C). 



16. MARCUSENIUS CASTOR. 

 Ulppopotamyrus castor, Pappenh. Sitzb. Ge*. nat. Fr. Berl. 1906, p. 260, and 

 Mitth. Zool. Mus. Berl. iii. 1907, p. 351, pi. ii. figs. 2 & 3. 



Depth of body equal to length of head, of to 4 times in total length. 

 Head 1-i- to 1^ times as long as deep, with curved upper profile ; snout 

 rounded, \ length of head, projecting beyond mouth ; mouth below 

 nostrils, its width \ length of head ; teeth bicuspid (truncate when worn 

 down), 5 in upper jaw, 6 in lower, median pair of lower teeth much 

 larger than the others ; nostrils equnlly distant from end of snout and 

 from eye, on a line with lower border of eye ; eye moderate, about § 



Fkr. 60. 



■in 



^£^&^ a " 



Marcustnias castor. 

 Type. i. 



length of snout and f interorbital width. Dorsal 31-32, its origin 

 corresponding to that of anal, its length f its distance from head. 

 Anal 32-35, nearer base of caudal than base of ventral. Pectoral 

 pointed, a little shorter than head, not quite twice as long as ventral, 

 and extending beyond root of latter. Caudal densely scaled on half of 

 its surface, with pointed lobes. Caudal peduncle 3 times as long as 

 deep, -| length of head. 85-93 scales in lateral line, ^ A in transverse 

 series on body, -| in transverse series between dorsal and anal, 16 round 



