148 Mr. O. Thomas on 



1 lie occuneiice of such a variation as this gives much food 

 for thought, especially to those who are interested in the 

 question as to whether species are ever developed by spas- 

 modic or discontinuous variation. It is evident that under 

 conditions of light or colour-suvroundings favourable to an 

 animal like the normal Tayra, black with a yellow breast- 

 ppot, the same patch on the upper surface might also prove 

 efl'ective, and that individuals possessing it might gradually 

 crowd out the normal coloured examples. In this way, 

 however spasmodically produced in the first place, the 

 abnormal colouring might become the mark of a peculiar 

 race or species. That this has not as yet taken place, 

 however, is shown by the normal examples taken with the 

 others already referred to. 



It would also have to be remembered that the Tayra, like 

 so many similarly coloured animals, is arboreal in its habits, 

 and that it' it often crawls along, back downwards, underneath 

 boughs, a similar reason for breaking up the mass of the 

 body-colour might obtain as with the breast-spot in the 

 nornial position. The curious yellow spot in the middle of 

 the back in male specimens of Bradypus offers a suggestive 

 parallel to the coloration of these abnormal Tayras. 



In addition the Tayra of the Island of Trinidad has 

 become so very much smaller than that of the mainland that 

 it also seems to deserve a peculiar subspecific name, and may 

 be called 



4. Galictis harbnra trinitatis, subsp. n. 



Size much smaller than in G. h. typica ; skull of male 

 101 millim. in basal length by 67 in greatest breadth, of 

 female 92 by 60. Colours as in the tj^Dical form. 



Hab. Trinidad. Type from the Caroni district. 



Type (female) B.M. no. 99. 2. 2. 1. Presented by 

 Henry Caracciolo, Esq. 



XVII. — New South- American Mammals. 

 By Oldfield Thomas. 



Cam's sechurcBj sp. n. 



Allied in essential characters of skull and dentition to 

 C. griseus, triay, and C. gracilis, Burm., but very different 

 externally. 



Fur short, coarse and harsh, quite unlike the soft fur of the 

 allied species, the hairs of the back barely 30 millim. in 

 length. General colour of upper surface coarsely grizzled 

 iron-grey, with a slight iulvous tinge; each of the longer 

 hairs of the back is light-coloured for its proximal third, 

 black for the middle third, the terminal third being white or 



