626 MR. ST. GEORGE MIVART ON THE CRANIA_[Nov. 22, 
The many forms to which the above characters apply may perhaps 
admit of being grouped together in certain subgenera, which may be 
distinguished as (1) Galago (Otogale), (2) Galago (Otolemur), (3) 
Galago (Otolienus), and (4) Galago (Hemigalago). 
The species which has been named by Dr. Gray* Otogale pallida, 
and of which he has figured the skull and external form, is repre- 
sented in the British Museum by two skins (types of the species), 
the extracted skulls of which are in the osteological collection. There 
is also a skin, with the skull inside it, which is the Otolicnus apicalis 
of M. Du Chaillu, and closely resembles O. pallidat. 
These species or this species has a somewhat different aspect to 
that of the rest of the Galagos. The tarsus may perhaps be rather 
shorter in proportion to the tibia than in the species forming the 
subgenus Galago (Otolicnus) (with which subgenus O. pallida has 
much affinity as regards its cranial characters), but I have only been 
able to observe skins. 
The skull is exceedingly like that of Galago (Otolicnus) sen- 
naarensis ; but it differs from that, and from all other species of the 
genus, in the greater relative production and more canine-like form 
of the first upper premolar. The mandible is very low at the sym+ 
physis, and has its angle produced downwards as well as backwards. 
The last upper molar is quadricuspidate ; but the last inferior molar 
is distinctly quinquecuspid in one individual, while in the other there 
ean hardly be said to be more than four cusps, on one side at least t. 
The next subgenus will include the Otolicnus garnettii of Ogilby ( Oto- 
gale garnettii of Dr. Gray), the Galago crassicaudatus of Geoffroy 
( Otogale crassicaudata of Dr. Gray) ; also a new species or variety 
* Proc. Zool. Soc. 1863, p, 140, pl. xrx. 
+ Dr. Gray considers it to be probably the same species: see note, /. c. p. 141. 
+ Not much reliance can, I think, be placed on the presence or absence of a 
fifth cusp on the last lower molar as a distinguishing character. Forms exceed- 
ingly alike in other respects differ in this, as in Galago (Otolemur). Not only 
may the same species vary (Professor Huxley noticed this to be the case in Nyc- 
ticebus), but the very same individual offer a different structure on the two sides 
of the same jaw, as in the above-mentioned Galago (Otogale) pallida. The same 
variation also obtains in quite other forms of the order Primates. Thus in Sem- 
nopithecus, characterized by having five tubercles to the last lower molar, I have 
observed that the species S. mitratus, S. cinereus, and S. nigrimanus (in the 
osteological collection at the British Museum) have only four tubercles to that 
tooth. M. Isid. G. St.-Hilaire has also noticed a similar condition in some 
species of that genus (Archives du Museum, t. i1.), and I have in my own collec- 
tion a skull of a species of the same genus which has s¢x distinct tubercles to the 
last inferior molar. Again, the Talapoin differs from the other species of Cerco- 
pithecus in having only three tubercles to the last inferior grinder, that being 
one of the characters on which M. Isid. G. St.-Hilaire founded his genus Mio- 
pithecus (Arch. du Mus. t. ii. p. 549, 1843). 
But not only is the last grinder thus variable in form, but an additional grind- 
ing-tooth is not unfrequently developed. Thus the last-named author noticed a 
fourth true molar on each side of the lower jaw of a Malbrouck (see article 
“Cercopithéque,” Dict. Universel d’ Hist. Nat. t. iii. p. 306), and a Cebus with a 
supernumerary molar on each side of the upper jaw. Dr. Peters also has de- 
scribed and figured (Reise nach Mossambique, pl. 4. fig. 3) a Galago (his Ofolt- 
enus crassicaudatus) with a distinct, though small, fourth true molar on each side 
of the upper jaw. 
