86 Mr. 0. Tliomas on 



wliicli L. hicoJor liad been evolved by the accidental occur- 

 rence and then gradual predominance of semi-albinistic 

 individuals of this normally coloured species. But the fact 

 that the very young specimen of L. martinsi has its face and 

 the sides of its crown clothed with silvery-grey hairs telU 

 against this thoory and in favour of the ancestors of both 

 species having had lieads of a grey colour. 



The rule that " Natura non facit saltum," which I believe 

 to be generally true of mammal coloration, has therefore 

 not got an exception in this marmoset, as I at first believed to 

 be the case. 



Dastjpterus ecfa, Gerr, 

 ? . 30. Faro. 



Mijotis nigricans, Wied. 

 ? . 2.8. Benevides, E.F.B., near Para. 



Saccopterycs bilineaia, Temm» 

 ^ . 22. Parana de Faro. 



Saccopieri/x leptiira^ Schr. 

 ? . 4, Benevides, E.F.B., near Para. 



Rhynchiscus naso, Wied. 



(?. 26, 29; ?. 27, 28. Faro. 

 S . 4. Apehu, E.F.B. 



Nociilio alhiventer, Spix- 

 ?. 7. Faro. 



Molossui olseurus, Geoff. 

 J . 9 ; ? . 13. Faro. 



L'umops triDnhuUij Thos. 



S. 32. Faro. 



{Sjiecimens from Ega in the collection of Mr. Tomes, 

 determined by him as is", perotis, also prove to belong to this 

 smaller Amazonian species. Examples of the three large- 

 toothed E. perotis are in the Museum collection from Lagoa 

 iSanta and Cordova; its type locality was the Parahyba 

 River, Hio Janeiro. 



