267 
seales. There is no indication of a tuft at its extremity, as in Z. 
cayennensis. 
The general colour of the upper parts is very dark brown, being a 
mixture of reddish-brown and black, the latter predominating ; the 
cheeks, sides of the neck, and sides of the body the same, but paler; 
around the eyes a narrow circle of black ; fore- and hind-feet and 
under surface of the tail ashy-brown, those on the upper surface of 
the tail black. There is much less naked skin on the inside of the 
thighs and on the pubal region in this species than in FZ. cayen- 
nensis. 
Besides its greater size, the skull of this species offers another 
peculiarity worthy of note, as may be seen by the drawings (woodcuts 
1, 2, 3, 4), which represent the skulls of Z. cayennensis and E. semi- 
spinosus. Taking for comparison, as before, the commoner species, 
E. cayennensis (figs. 1, 3), the nasal bones of its cranium are seen to 
extend backward barely as far as to the anterior root of the zygoma, 
and to retain their full breadth for the whole of their length, and 
the intermaxillary bones each to end in a point about one line poste- 
rior to this. In E. semispinosus (figs. 2, 4) these proportions are 
reversed : the nasal bones, extending farther back, become narrower, 
and end in a point on the frontal region, while the intermaxillary 
bones do not reach so far back as the zygoma, and terminate abruptly 
instead of being produced to a point. The orbit also in this species 
is of greater relative size, which is further increased by the backward 
position of the process of the superior margin of the zygoma. 
“ “ 
Length of the head and body .......... 0 
NEE oe pontiac nom As 'atop ty 27 
2, BE ea aa Date 5 6 
of the ears behind.............. 0 7% 
Breadth of the ears, nearly ............ 0 7 
« Length from nose to eye .......... Pea aad | 
from nose to ear ........... 0. 1-92 
of fore foot and claws .......... eee 
6fthe middle’ claw +70 2220.55) °° O° 2B 
of hind foot and claws .......... 1 10 
of the middle claw ............ 0 3 
Of aeeene OFM... ks. ss «621 6 
at Ceti EAT ESD, ; 2 2 
Total length of skull.................. 2 22 
Breadth across the zygomatic arches...... 1 12 
Length from point of upper incisors to an- 
terior MOlAR igi es aw wares sha» diatige 179.0: | 62 
of molar range ................ 0, Az 
of nasal bones ...... Suewpets eaten O0 1OF 
of lower jaw from point of incisors 
.to condyloid process ................ 1 42 
Depth from the condyle vertically ...... 0 7 
Three specimens of this species have been received in spirits, all 
