110 ON DACTYLOMYS DACTYLINUS ETC. 



agree much more with Lasiuromys . Loncheres and Echimys ; 

 D. dactylinus lias a typical rat-tail , at first sight naked , 

 so extremely small and short are the few hairs upon it ; 

 K, amhlyonyx on the other hand has a very hairy tail , 

 more like Lasiuromys villosus and ending in a tuft of 

 long hairs like in Loncheres hispida. * 



It seems to me very puzzling that amhlyonyx up to this 

 date always has been regarded as belonging to the genus 

 Dactylomys and I think that lack of material has been the 

 mere reason why it not rather has been enregistered as 

 a Loncheres with some species of which genus — f. i. 

 with Loncheres hispida — it has indeed much more in 

 common (in external characters , in shape and hairiness of 

 tufted tail , in size , in form of skull , in form of bony 

 palate , in color of the molars , a. s. o.) than with Dacty- 

 lomys dactylinus , notwithstanding L. hispida has spiny 

 hairs and sharply pointed curved claws. 



Some measurements of the skull of an adult specimen 

 of Kannabateomys amhlyonyx in our Museum : 



Length of skull 58 Mm. 



Width between zygomata 28.5 » 



Length of nasal bones 16 » 



» » upper molar series 14 » 



» » lower » » 15.5 » 



Diastema upper jaw 12 » 



The molars of Dactylomys dactylinus are white colored, 

 those of Kannahateomys amhlyonyx reddish brown; in both 

 species the incisors are smooth and orange colored. 



Habitat of Kannahateomys amhlyonyx: Brazil, Province 

 San Paulo (Göldi), Ypanema (Natterer), Prov. Minas Ge- 

 raes (Museum at Rio de Janeiro, vide Göldi, 1. c. p. 230), 

 Prov. Rio de Janeiro , Porto Real (Leyden Museum), Porto 

 Alegre (Winge), and Prov. Rio Grande do Sul (Hensel). 



Notes from the Leyden JMuseuixi, Vol. XIII. 



