98 DR. E. A. GOELDI OX MARMOSET [Jan. 15, 



department of mammals at the British Museum, to my no small 

 surprise showed me a small series of skins from different points 

 in the Upper Amazon region, one having been furnished by 

 Dr. von Ihei-ing, from the River Jurua expedition. 



After my return to Para I saw by the ' Revista do Museu 

 Paulista,' vol. vi. (1904), p. 416, which had been sent in my 

 absence, that Dr. von Ihering refers to three individuals in the 

 collections made by Mr. Garbe at the time of the above men- 

 tioned Jurua trip. He, however, classifies it as a new subspecies 

 — M. pileatus juriumus — which according to his statement is 

 distinguished by the dark colour of the hair of the back, which in 

 the description of the original type-specimen, made by Geoffroy, 

 is stated to be reddish at its base. It is true, that Geoffroy expresses 

 himself in the following terms : — " Le corps est superieurement re- 

 convert, ainsi qu'on I'observe si souvent chez les Hapaliens, de 

 polls roux dans la plus grande partie de leur etendue, anneles de 

 blanchatre et de noire vers la pointe. II resulte de cette dis- 

 position, chez M. pileatus, un melange de gris et de noir, mais 

 non des bandes alternatives de I'une et de Faiitre coulevir." 

 Although the adjective " roux " may not be perhaps a happy 

 term, the rest of the description and the figure itself indicate 

 an animal which does not difier essentially from the specimens 

 examined by me in London, nor from my two mounted speci- 

 mens here at Para. Geoffroy evidently wrote with the desire to 

 differentiate the uniform general colouring of this species (which, 

 as already seen, is iisually a common feature of most Amazonian 

 Callitrichidse) from the distinctly striped colouring of certain 

 southern Marmoset Monkeys (HajKile jacchtis, &c.). 



On separating the fur of the back of my two individuals in the 

 Para Museum, the hair appears to be of the same deep blackish- 

 brown as in the case of M. griseovertex. The terminal fourth 

 then shows a light greyish-white zone, followed by a terminal 

 nearly black one. It follows therefore that in this detail my 

 Purus specimens accord with the Jurud specimens of Ihering. 

 However, this detail does not seem to me of sufiicient weight to 

 justify the establishing of a separate subspecies. 



Midas mystax Spix. 



Acquaintance and description of this species date from the 

 same period and come from the same source. Spix brought his 

 specimens from the River Solimoes ; a female is figured on plate 22 

 of his work. Our Museum possesses a considerably darker male 

 specimen from the River Jurua. 



Instead of entering into a detailed description, I would simply 

 call attention to the characteristic fact, that the white circum- 

 buccal zone is nearly identical in extent and form with that of 

 the preceding Midas pileatus, but with a stronger tendency to 

 form a moustache. 



