4 OLDFIELD THOMAS 
and Cattaneo on the anatomy of the genus /eterocephalus (+). . 
Without going again into the history of the genus, amply 
detailed by these authors, I may recall that the first species, 
H. glaber, was described by Ruppell from Shoa, and the second, 
H. phillipsi, by myself from Ogaden, Somali-land, this form being 
mainly distinguished from the first by its great inferiority in size. 
When therefore Parona and Cattaneo obtained for examination 
from the Marquis G. Doria a specimen from a series obtained 
in Somali-land, some of them actually from Ogaden, and this 
specimen proved to be precisely similar in size and other cha- 
racters to the original Shoan H. glaber, it was not unnatural 
that they should suppose my distinction of H. phillipsi to have 
been wrong, and merely based on a young specimen of the 
older known form. 
I myself, especially after examining the peculiar age-changes 
observable in the skulls of Myoscalops (?) and seeing then how 
difficult it is to be always sure of the age of any given specimen 
of this group, had had great doubts on the subject, and I have 
therefore been proportionally pleased on now finding that after 
all H. phillips’ is a perfectly valid species, and that the diffe- 
rences noted in my paper are in no way due to age, but are 
genuine specific characters. 
This conclusion is based on the examination of three specimens, 
two adult and one young, all from Somali-land, and collected 
by Capt. Bottego. One of the adult specimens has been most 
generously presented to the British Museum by the Marquis 
G. Doria, and the other two lent for the purposes of the present 
paper. 
The proof of the distinctness of H. phillips: lies of course in 
the characters of the young specimen of H. glaber, which, 
although clearly far younger, is nevertheless already larger than 
the type of H. phillipsi, thus at once ‘disproving the theory as 
to the youth of the latter. 
(1) Ann. Mus. Civ. Genova (2) XIII. 1893. p. 419. 
(2) See P. Z. S. 1890, p. 448. 
