i 6 MOKMYRID.E. 



Marcusenius isidori, Bouleng. Proc. Zool. Soc. 1898, p. 798, and Fish. Nile, p. 42, 

 pi. vii. fig. 1 (1907). 



Depth of body 2f to 3|- times in total length; length of head 4 to i\ 

 times. Head as long as deep ; snout \ to \ length of head, rounded, 

 projecting beyond mouth ; mouth situated below nostrils, its width 4i 

 to 5 times in length of head ; teeth bicuspid, 7 in upper jaw, 8 in lower ; 

 anterior nostril on a line with centre of eye, midway between latter and end 

 of snout ; posterior nostril close to eye, near its lower border; eye moderate, 

 as long as snout, \ to f interocular width. Dorsal 18-22, originating 

 above 3rd or 4th ray of anal, its length about half its distance from head. 

 Anal 22-26, nearly equally distant from base of ventral and from base of 



Fig. 59. 



Marcusenius isidori. 

 Nile Delta (F. N.). 



caudal. Pectoral pointed, subfalcate, as long as or a little shorter than 

 head, 2 to 2\ times as long as ventral, and extending beyond root of 

 latter. Caudal with pointed lobes. Caudal peduncle 2^ to 3 times as 

 long as deep, as long as or a little shorter than head. 53-60 scales in 

 lateral line, ^^ in transverse series on body, y^ 2 in transverse series 

 between dorsal and anal, 16 or 18 round caudal peduncle. Brown on 

 the back, silvery white beneath, uniform or dotted with brown. 



Total length 100 millim. 



Nile, from the Delta to the Bahr-el-Gebel. — Types in Paris Museum. 



1-2, 3-5. Ad. Lower Nile. Dr. Ruppell ((!.). 



6-7. Ad. Rosetta Nile, near Barrage. L. Loat, Esq. (C). 



8. Skel. „ „ „ 



9-11. Ad. & hgr. Nile near Cairo. Capt. S. Flower (P.). 



12. Al. Lahun, Fayum. L. Loat, Esq. (C). 



13-16. Ad. & hgr. Between Assiut and Abu Tig, „ 



Lower Nile. 



17-36. Ad., hgr., & yg. Luxor. „ 



