io FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. XII. 



tion in the number of scales along the lateral line, including those on the 

 base of the caudal rays, is expressed in the following tabulation: 



Barbus athi sp. nov. 



Plate I 



Type specimen, a mature male 152 mm. long to end of last vertebra, 

 Cat. No. 6108, Field Museum of Natural History. The description is 

 based upon the type and io paratypes (Cat. No. 6109), which vary in 

 length from 105 to 132 mm. Fifty-five other specimens, ranging in 

 length from 21 to 103 mm., were secured (Cat. No. 6 no). 



This species is a member of the B. hindii group. 



From hindii, which is recorded by Boulenger from the Athi River, 

 it differs in the less robust form of the body, but deeper caudal peduncle, 

 in the much shorter dorsal spine, and from the type in the lower num- 

 ber of scales along the lateral line. 



Our species is probably most closely related to Barbus krapfi 

 Boulenger, 1 from the type description of which it differs in the shorter 

 pectoral fins (much shorter than the head), in the longer head, with 

 shorter and blunter snout, and in the shorter barbels; the head is con- 

 tained 3.2 to 3.3 times in the length, rather than from 3^ to 3 4 /s times; 

 the snout is contained 3.1 to 3.35 times in the head, instead of from 

 3/4 to 3^ times; the posterior barbel at most is x /6 longer than the eye 

 (iX to i >^ times eye in krapfi}, and the anterior barbel is usually shorter, 

 at most barely equal to, the diameter of the eye (i to i>^ times eye in 

 krapfi}. As the type specimen is mature, and as the eye has attained the 

 small relative size given by Boulenger for the adult of krapfi, we are 

 unable to attribute these differences to age-variation. It is probable 

 that the specimens which Boulenger records from the Limba River, a 

 tributary of the Athi, as the young of his krapfi, are referable to B. athi. 



Barbus ahlselli Lonnberg 2 is another closely related species; it differs, 

 however, in its more slender form, larger eye, narrower interorbital, 

 and higher dorsal. 



Barbus mawambiensis Steindachner, 3 a West African species of the 

 same group, has a relatively deeper caudal peduncle and higher dorsal. 



1 Cat. Fresh- water Fishes Africa, 2, 1911, p. 54, text fig. 

 1 Kungl. Sv. Vet. Akad. Hand., 47, 6, 1911, p. 39. 

 * Denkschr. Akad. Wiss.JWien, 89, 1913, p. 25. 



