228 On the Glans Penis in Macaque Monkeys. 
the penis, with the orifice as a vertical terminal slit extending 
further on to the dorsal than the ventral side, and eccentric 
in the sense that it lies to the right of the middle line, being 
pushed as it were out of place by ‘the end of the baculum, 
which is actually in the middle line alongside it. There is a 
wide and deep angular excision on each side of the glans and 
a much smaller one in the middle of its posterior border above. 
The surface is covered with small spicules (fig. 2, A-F). Ina 
general way the glans of Papio, Cercocebus, Cercopithecus, and 
Pithecus (Presbytis) is like that described above; but in 
M. sinicus it is modified, although not in the direction leading 
to the specialization seen in MZ. fuscatus and speciosus. It is 
more coarsely spicular, slightly pointed at the apex, and 
hence regularly or irregularly piriform when seen from above ; 
but the posterior portion of its upper side is developed into a 
transverse crescentic thickening with its concavity looking 
forwards (fig. 2, G-K). 
In the foregoing paragraphs the species therein discussed 
have been referred to the genus Macaca; but the monkeys 
commonly called macaques are a heterogeneous mob divided 
by authors of the present time into a number of genera and 
subgenera which are based for the most part upon unsatis- 
factory characters of very little systematic value, such as the 
length of the tail, the arrangement of the hairs on the crown 
of the head, and so forth. Thus we have Macaca for tnuus 
(the Barbary macaque), Silenus for albibarbatus (the wanderoo 
of textbooks), Zati for sinieus (the bonnet macaque), ete. 
These and other names, with their synonyms, may be found 
in Allen’s paper (Bull. Amer. Mus. Nat. Hist. xxxv. pp. 49- 
51, 1916). 
It is beyond my present purpose to discuss these genera 
and subgenera except in so far as tle penis is concerned. 
Unfortunately I am only acquainted with that organ in com- 
paratively a few forms. Hence a complete revision of the 
genus Macacu, in the widest sense of that name, is impossible. 
I think, however, that all systematists will agree in the 
impossibility. of classifying speciosus and fuscatus in the same 
genus as sinicus, irus, rhesus, and nemestrinus; and it must 
be admitted as probable that other species will be found 
agreeing with the first two in the particulars connected with 
the penis described by Anderson and Murie. For these two 
forms the name Lyssodes, Gistel, of which spectosus is the 
type, is available. Moreover, the structure of the glans penis 
is a useful character for eliminating sinicus from the last three. 
For sinicus, Zatt, Reichenbach, appears to be the correct 
title, but, pending the discovery of satisfactory evidence that 
