ALOUATTA 279 



I have examined the series of specimens in the American Museum 

 of Natural History in New York, from Colombia, including the types 

 which Dr. Allen has separated from A. seniculus, as A. s. rubicunda 

 and A. s. caucensis, and am unable to find characters in my opinion 

 sufficient to cause them to be elevated to a distinct rank. In the table 

 of measurements given at the end of his paper, sixteen specimens of 

 A. s. rubicunda and eight, only half as many, of A. s. caucensis have 

 been selected. This has been done by Dr. Allen, not from his own 

 volition, but because he did not have sufficient material from the 

 Cauca Valley to enable him to equalize the two series in the number 

 of examples apportioned to each. These subspecies were established 

 upon cranial characters chiefly, although the color of the specimens 

 was not disregarded. As to the latter I find that Cauca Valley speci- 

 mens have practically perfect representatives from Bonda, Santa 

 Marta district, and Dr. Allen speaks of the "great local variation 

 abundantly shown by a fine series of nine specimens from the Upper 

 Cauca Valley collected at altitudes of from 3,000 to 6,000 feet" and 

 of the A. s. rubicunda he states, this large series (examples), "shows 

 a wide range of variations in color, which proves to be entirely inde- 

 pendent of sex or age and largely independent of season." This agrees 

 with my own experience of A. seniculus with the large series of these 

 animals examined in the collections of the various European Museums. 

 More or less slight variations in depths of shades, seen in specimens 

 from the same or contiguous localities cannot therefore be relied upon 

 as a character for establishing a race for this species, and I have shown 

 in my remarks on the crania that the skulls, even of specimens from the 

 same locality, vary in an almost incredible degree. Dr. Allen in his 

 paper has given figures of the skulls of his two subspecies, which, if 

 taken by themselves would seem to show that he had ample grounds 

 for giving them distinctive rank, but on examining these crania, the 

 differences exhibited, either disappear or are shown not to be confined 

 exclusively to either form. At first sight of the figures exhibiting the 

 under side of the skull, one is struck by the curvature of the tooth 

 rows in the cranium of A. s. rubicunda, a feature not found in any 

 individual of the A. seniculus type. On examining this skull it was 

 seen that the last molar was abnormally placed, was out of its proper 

 position, the one on the left side, (right side of the figure), was situ- 

 ated farther inward than the corresponding tooth on the opposite side, 

 which was only slightly out of position, and this accounted for the 

 curvature seen in the figure. The other skulls from the same locality 

 had the tooth row perfectly straight as exhibited by the figure of the 



