ON ARCTOCEBUS CALABARENSIS 595 
front and the hinder boundary of the external ear. Hence the 
aperture of the external ear is directed forwards as much as outwards. 
The pinna has no distinct lobule; the tragus (¢) is very small; the 
helix (#) is represented only by the thin edge of the pinna; the 
antihelix (@.2) is more distinct, and divided 
in front and above into two branches ; at 
its base, inferiorly, a small antitragus ap- 
pears. The fossa innominata, which sepa- 
rates the helix and antihelix, is obsolete, 
except inferiorly, where it forms a deepish 
pit behind the antihelix. 
The two singular transverse ridges 
(a, 6), which lie above the auditory meatus 
and anterior to the upper end of the anti- 
helix, described and figured by Dr. Smith, The left ear of the Angwantibo. 
are 0°25 inch long and about o'1 inch high ; 
they are separated at their bases by an interval of about o'1 
inch, but their free edges approach more closely. Fine hairs spring 
perpendicularly from the opposed margins of these ridges, and 
interlock with one another. 
The length of the body is only 9°8 inches, instead of 10} inches. 
The tail, however, has the same length (0°25); and the other mea- 
surements are very similar to those of Dr. Smith’s specimen, thus :— 
inches. 
The breadth of the head in front of the ear is .........cce eee I's 
The breadth of the head in front of the eyes is ......... ...... 
Mesian line of nose to anterior part of meatus auditorius .... 
Point of nose to anterior angle Of CY€......... cece reenter tees 
Anterior angle of eye tO €af oe... i ciees cette teeter ett tee 
Total length of head ............-:: eee 
Eyerslit...... cccccceeeeeeeereee reese rneeereerncnes 
Distance between inner canthi 
Ear, antero-posteriorly (when flattened oul) ......-: ere 
Ear, vertically .........cccccceeceee ree eneee cee teen etree etter resent ern ees ns 
The measurements of the limbs also agree very well with those 
given by Dr. Smith (4 « pp. 184, 185). Thus I find the distance 
from the 
Point of shoulder to the elbow to be... cee cee cette eee eee e ee teeta B15 
Elbow to Wrist ...cccecceee eee eee see ee rete re ree ett reese nenen eee ent ns 
Wrist to point of fourth finger 
Great trochanter to kne€ ...-.. sss eee eee eee ee cette 
Knee to ankle .........cccce cee crnee eres cence a tee een ees : 
Foot from ankle-joint to point of fourth t0€ ....6. i oe 1's 
