118 Bulletin American Museum of Natural History [Vol. LXXII 



Hahn's monograph, a long-needed review of recent and fossil Hyra- 

 coidea, is based on the excellent collections in Berlin, Frankfort and 

 Tervueren, together with notes compiled by the late Doctor Brauer on 

 collections in other continental museums. It is unfortunate that the 

 author had no opportunity to examine the British Museum Collection 

 nor any of the material in America, specimens which are of im- 

 mense importance in any study of this group of animals. Included 

 in the work is a sound discussion of the skull and skeletal characters, 

 used as criteria of relationship, together with a dissertation on the 

 ecological and zoogeographical background of hyrax phylogeny. 



Most of Hahn's conclusions appear sound, particularly as regards 

 the main phyletic trends. As may be seen in the following treatment 

 there are, however, numerous points on which I cannot agree with him 

 concerning the taxonomy of Congo forms. Thus, it appears to me highly 

 probable that Dendrohyrax d. latrator must be recognized; and I am 

 convinced that there is no basis, other than Hahn's failure to recognize 

 dichromatism, for considering the tree hyraxes of the northeastern Congo 

 as anything but homogeneous. The fact that in the monograph my 

 Heterohyrax chapini was listed under another species was due obviously 

 to the fact that my previous report on the Order did not appear until it 

 was too late for Doctor Hahn to give it consideration. The omission in 

 Hahn's revision of all reference to types and type localities is an unfor- 

 tunate neglect, particularly in that his predecessor, Brauer, so fre- 

 quently made no mention of the number, sex or age of his types. Ap- 

 parently overlooked in the review was Dendrohyrax rubriventer Brauer 

 (= D. d. emini Thomas). 



It is again my pleasure to tender my thanks to Doctor James P. 

 Chapin for his invaluable advice; and to the authorities of the Field 

 Museum, the United States National Museum, the Museum of Compara- 

 tive Zoology and the British Museum for their courtesy in permitting the 

 examination of collections in their charge. 



The text figures in this Bulletin were drawn by Marcelle Roigneau 

 Hatt and the photographs of animals in the flesh made by Mr. Lang. 



