96 DR. E, A. GOELDI ON MARMOSET [Jan. 15, 



but a little lighter in all specimens. Fore-arms and hands 

 gradually darker towards the extremity. This is especially the 

 case in the three young specimens and the old female, while the 

 male shows on the outer side of the fore-arm and hands the same 

 <lark greyish cast as noted above in the description of his face. 



Legs. Outer side of thigh the same colour as the back, but as a 

 rule a little lighter, especially in the old female. The outer 

 side of the foot is of the same dark colour as the hand. 



Ventral aspect. — The colour forms a marked contrast with 

 that of the dorsal aspect, by having a pronounced tendency towards 

 a rusty red, especially in the younger specimens. This rusty-red 

 shade covei's the whole under side, from the throat backward in- 

 cluding the inner side of the arms and legs and no small extent of 

 under "side of tail. The same colour tends to form regions or 

 patches of a deeper shade, one between the arms, covering the chest, 

 and another between the legs, covering the abdomen and svir- 

 rounding the anus. The chest-patch, especially in the old female, 

 looks as if soiled by dried blood. 



Tcdl. The tail is long, nearly half as long again as the body 

 (the average length of four specimens measured being as 11 : 8). 

 In the younger specimens the dorsal side neai-ly from the inser- 

 tion to the end is of the same dark colour as the feet, while the 

 lower side shows a gradually narrowing line of the above mentioned 

 deep lusty red fading toward the extremity. In the adult 

 specimens the colour of the tail tends to become uniform in its 

 whole circumference. In the old female the upper side is darker 

 than the lower at least for two-thirds of its length, the terminal 

 third being of a dark grey, due to the black roots and the light tips 

 of the hairs. The under side for about half its length has the general 

 lio'ht rusty-red colour of the ventral aspect, the terminal half 

 being alike on the dorsal and ventral side, a dark grey. 



Most aberrant is the colouring of the tail in the old male. 

 From the very insertion the bright rusty-red colour predominates 

 in its whole circumference throughout its entire length with the 

 exception of a dark terminal tuft. The rusty red is most 

 noticeable to a ceitain extent (one-eighth) from the insertion 

 backward. Approaching the end the colour is more mixed with 

 dark owing to the greater extent of black at the roots of the 

 individual hairs. A darker isolated patch exists also on the 

 second eighth. 



Midas fuscicollis Spix. 



This species, it is true, was long ago described, having been 

 introduced into science in 1823 by the Bavarian explorer J. von 

 Spix from individuals obtained on the Rio Javary, but it is 

 evident fi-om our much richer material (eight specimens, & S S 

 and 2 § $ ), collected on the Rio Purtis, that the pelage of 

 the full-grown animal has never been pi-operly described and 

 figured. Referring to a comparison of the two figures 3 (adult 

 coat) and 3 a (juvenile coat) of my oiiginal coloured Marmoset- 



