EAST AFRICAN REPTILES AND AMPHIBIANS 97 



RANA ABERDARIENSIS Angel 



Rana aberdariensis Angel, 1925, Reptiles et Batraciens, in Voyage de Ch. Al- 

 luaud et R Jeannel en Afrique Orientale, (1911-12), pp. 42-46, pi. 2, figs. 1 

 and 2. (Mt. Kinangop, Aberdare Mtns., Kenya Colony.) 



12 (U.S.N.M. 40689, 40711-12, 40732-4, 40973-4, 41006, 43008-10) 



Mt. Kenya, K. C. (Sm. Afr. Exped.) 1909. 

 11 (U.S.N.M. 41337-47) Mt. Kenya to Fort Hall, K. C. (Sm. Afr. 



Exped.) 1909. 

 33 (U.S.N.M. 41714-41,41752, 41761, 41765, 41772, 41792) Wambugu, 



K. C. (Sm. Afr. Exped.) 1909. 

 7 (U.S.N.M. 43098-100, 43113, 43177, 49081, 50949) Kenya Colony. 



(Sm. Afr. Exped. and Heller) 1909-12. 



This long series of aberdariensis convinces me that the species is 

 recognisable and that I was in error when, with my colleague/* we 

 placed it in the synonymy of Rana nutti. At that time we had not 

 seen a male and overlooked the significance of the author's statement 

 that his single male "pourvu de plis de peau tr^s minces, de chaque 

 cote de la gorge pour la sortie des sacs vocaux." I find that the 

 males may be distinguished readily from those of either nutti or fus- 

 cigula by the sides of the throat being dark blue grey over the small 

 skin folds of the vocal sac region ; moreover, in males of aberdariensis 

 the center of the throat is always white while in nutti it is rarely 

 white, for it is usually mottled; in fuscigula it is apparently always 

 mottled. 



Whereas Angel had only a single male and four adult females the 

 above series is comprised of 31 males but only 9 females. The sug- 

 gestion that at the time the series was collected the males had as- 

 sembled in the pools but that the females had only begun to arrive 

 can not be maintained in view of the numerous young also collected, 

 unless the breeding season is an extensive one. It may be observed 

 that at least one female was received from each locality. Naturally, 

 the great preponderance of females over males in the series of nutti 

 raised doubts as to whether or not some aberdariensis females had 

 not been included in error. This is not the case, for it was discovered 

 that besides the shorter leg length of aberdariensis the two species 

 may be sorted on the basis of the vomerine teeth which in aberdari- 

 ensis are in two small round groups but in nutti are in elongate series. 

 This character is a little difficult to gauge without practice in a large 

 series and I have found it of no use in trying to separate the young 

 of these two species. 



Males may be readily distinguished from the females by the 

 swollen base of the first digit, a critical examination of the series 

 of 31 males shows a range in length from 46 to 58 mm., with an 

 average of 50.8 mm. Other characters may be listed serially as 

 follows: 



" Barbour and Loveridge, 1928, Mem. Mus. Comp. Zool., vol. 50, p. 191. 



