MAECUSEXIUS. 



37-4(1. Ad., hgT., & vg. Between Luxor and Assuan. 



47. Ad. Assuan. 



48. Hp-r. Lake No, White Nile. 



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



77 



L. Loat, Esq. (C). 



16. MARCUSENIUS CASTOR. 

 Uippopofami/rns castor, Pappenh. Sitzb. Ges. nat. Fr. Berl. 190G, p. 2G0, ond 

 Mitth. Zool. Mus. Berl. iii. 1907, p. 3J1, pi. ii. figs. 2 & 3. 

 Depth of body equal to length of head, 3| to 4 times in total length. 

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

 rounded, ^ length of head, projecting beyond moath ; mouth belo\y 

 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 equally distant from end of snout and 

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



Fi-. 60. 



,, ;'ii|iji|;,,i ,j^. i^»f'l^^'iu,/iyj^tvj^^ 





€* 



Marciisenias casfo7'. 

 Type. k. 



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, f length of head. 85-93 scales in lateral line, l^ in transverse 

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



