6 EINAR LÖNNBERG, REPTILES. 



In A. the third and ninth maxillary teeth are enlarged, and fit in notches on 

 the lower jaw; in B. it is the fourth and tenth; in C. it is also the fourth and tenth; 

 in D. it is the second and eight on one, and the third and ninth on the other side. 



In the lower jaw the first and fourth teeth are enlarged in all specimens and 

 fit in a groove resp. a notch in the upper jaw. 



The twelfth tooth of the lower and the fifteenth in the upper jaw are also, as 

 a rule, more or less enlarged and fit into larger grooves in the opposite jaw than 

 their neighbours. 



According to the literature 1 it should be characteristic not only for the Nile- 

 Crocodile but for the whole genus Crocodilus that the fifth maxillary tooth is the 

 largest in the upper jaw. As has been stated above this is not the case in my spe- 

 cimens from Guaso Nyiri in which it is the fourth, the third, or even the second. 



Fig. 2. Dentition of a Crocodile from Guaso Nyiri (specimen B.). 



In the latter cases the snout may probably have been damaged during life time, and 

 one or two teeth together with their alveoles broken away, but in perfect specimens 

 it is the fourth maxillary tooth which certainly is larger than the fifth and the lar- 

 gest in the whole jaw. This apparent discrepancy seems to be of importance, but 

 Boulenger has (1. c. p. 276 note) given the explanation with the following words: 



»The young have five teeth in each prsemaxilla — the second tooth disappears 



with age - - — — in Crocodilus cataphractus, niloticus, and porosus.» This disap- 

 pearance is, however, so complete, and does not leave any marking on the jaw, so 

 that it appears inopportune to use as a generic characteristic the expression »fifth 

 maxillary tooth largest». 



The Crocodiles of Guaso Nyiri were sometimes intensely tinged with green on 

 the sides of the belly. The skin in the mouth between the rami of the mandible 

 had a light grey ground colour with large partly yellow partly olive-green spöts. 



1 For instance Boulengek Cat. of Chelonians Brit. Mus., p. 274 and p. 277, and Gadow Cambridge Nat. 

 i list. Series, Reptiles, p. 454. 



