218 REPORT ON ZOOLOGY, MDCCCXLIV. 



acknowledgment of both species ; of M. straminem he has as yet observed 

 only one example, while in M. ntfimanm he has likewise found the female to 

 be black ; he says nothing about the young. As to whether he observed the 

 M. flamcaudatus in a wild state, no mention has been made ; in accordance 

 with its circuit of distribution, it ought certainly to be regarded as a distinct 

 species. 



In the very puzzling genus Celus, Tschudi records three distinct species 

 as inhabiting Peru. They are the C. robust us, Neuw., cap^^cinus, and 

 ulbifrons, of which the right to be considered a separate species has with 

 the first always remained to me a doubtful matter. Meanwhile I would 

 observe that I now set apart the C. gracilis species as one distinct from 

 C. kypoleucos, after a comparison of several specimens brought over by 

 Nattcrer ; as likewise the C. xantliosternus, Neuw. (XantAocep&alws Sp.), 

 which appears to belong only to the coast lauds, and a C. nigruittatus, 

 brought over by Natterer from Upper Rio branco. An intimate acquaint- 

 ance and record of the local ranges of these Apes may assist us in separating 

 Iliem into species, or at least into constant local varieties ; in studying from 

 collections, without exact information as to the spots where they were found, 

 we remain the prey of mere conjecture. With the Capuchins then we will 

 have no more to do until its species have been firmly established. 



Of the genus Callithrix, which is rich in species, Tschudi has only found 

 two species in Peru, C. personata, and amicta. He regards the C. nigrifons 

 Sp., as only an aged individual of C. personata, but to this conclusion 

 I cannot, after a comparison of fourteen specimens that perfectly coincide 

 with each other, thirteen of them having been imported by Katterer, give 

 my assent. On the contrary, I now look upon C. nigrifons, after having 

 become better acquainted with it, as entitled to constitute a distinct species, 

 peculiar to the southern provinces of Brazil, and characterized by the follow- 

 ing diagnosis. C. brunesceus : taenia froutali lata mauibusque nigris. C. 

 Giffot Sp., occupies a place in the north-east of Brazil, being sordide 

 canescens, stria augusta froutali mauibusque nigris. Our specimens and 

 the two in the museum at Vienna arc labelled " from Bahia," and bear a 

 complete resemblance to each other, so that C. Gigot must be viewed as a 

 distinct species, or at least as a constant variety of C. nigrifons. C. 

 mclanocJdr, with which I am not acquainted through personal observation, 

 as neither the Bavarian or Eastern States travellers have found it, is dis- 

 tinguished from the two others by its chesuut-brown loins. Above all 

 these, as specifically different from C. personata, is C. cinerascens Sp., 

 both from its smaller size and shorter covering of hair, as well as its range 

 of distribution on the Peruvio-Brazilian borders. It may be thus charac- 

 terized : C. cinerascens, dorso-dilute fcrrugineo-brunescentc, manibus griseis, 

 cauda uigricaute ; statura C. cuprcaae. Chrysotlirix and Nyctipithecus, are 



