322 CHAEACINID^E. 



This Alestes is known from two specimens from Lake Victoria, obtained by Mr. E. 

 Degen at Entebbe, on Aug. 24th, 1905. It has been named after Col. Hayes Sadler, 

 H.M. Commissioner, Uganda Protectorate, at the time of Mr. Degen's visit. 



Measurements (in millimetres). 



Total length 94 



,, „ (without caudal fin) 86 



Greatest depth 26 



Length of head 21 



Width of head 10 



Length of snout 6 



Diameter of eye 7 



Interorbital width 8 



Longest ray of dorsal 20 



„ „ anal 10 



Length of pectoral 20 



A. sadleri is easily distinguished from A. nurse, to which, at a first glance, it bears a 

 very striking resemblance, by the more posterior position of the dorsal fin, by the 

 greater number of rays in the anal fin, and by one series more of scales between the 

 origin of the dorsal fin and the lateral line. 



4. ALESTES NURSE. 

 (Plate XIX. figs. 1 & 2.) 



Myletes nurse, Riippell, Fortsetz. Reschr. Fische Nil, p. 12, pi. ii. fig. 3 (1832). 



Myletes guile, Joannis, Mag. Zool. 1835, iv. pi. ix. 



Alestes nurse, Miiller & Troschel, Hor. Ichthyol. i. p. 13 (1845) ; Cuvier & Valenciennes, Hist. 



Poiss. xxii. p. 188 (1849) ; GKinther, Petherick's Trav. ii. p. 343 (1869) ; Steindachner, Sitzb. 



Ak. Wien, lxi. i. 1870, p. 544 ; Boulenger, Ann. & Mag. N. H. (7) viii. 1901, p. 488 ; 



Lonnberg, Ann. & Mag. N. H. (7) xii. 1903, p. 37. 

 Chalceus guile, Cuvier & Valenciennes, t. c. p. 255. 

 Brachyalestes nurse, Giinther, Cat. Fish. v. p. 314 (1864). 



Brachyalestes ruppellii, Giinther, t. c. p. 315 ; Pfeffer, Thierw. O.-Afr., Fische, p. 43 (1896). 

 Alestes leueiscus, Giinther, Ann. & Mag. N. H. (3) xx. 1867, p. 114. 

 Alestes ruppellii, Griinther, Petherick's Trav. ii. p. 343; Vinciguerra, Ann. Mas, Genova, xxxix. 



1898, p. 257. 



Body strongly compressed, its depth twice and a half to three and three-fourths times 

 in the total length ; length of head three and a half (young) to four and three fifths 

 times. Head once and two-thirds to twice as long as broad, as long as deep or a little 



