458 PROFESSOR J. ANDERSON ON THE 
this foramen and the three previously mentioned foramina, and at a considerably higher 
level than it, there is a well-marked foramen below and slightly anterior to the post- 
orbital process. It is directed upwards and rather backwards, apparently leading into the 
frontal sinuses; at least a fine wire inserted along it does not appear in the cranial cavity. 
The spheno-palatine canal is of moderate size, and opens at a short distance anterior to 
the sphenoidal fissure, and rather on a line external to it. Its lower border is formed 
by the pterygoid plate of the palatine. The posterior palatine canal is very short, and 
opens anterior to the external angle of the slightly thickened posterior margin of the 
palate. The anterior palatine foramina are bounded in front, within, and externally by 
the premaxille, and posteriorly by the maxillz. The lachrymal foramen, which opens into 
the orbit above and rather external to the infraorbital foramen, is marked at its anterior 
border by a strong process that projects outwards and slightly backwards, being con- 
tinued upwards along the margin of the orbit to near the postorbital process as a 
distinct ridge as in Erinaceus; and, as in that genus, the prelachrymal process itself is 
perforated by a minute foramen. Externally the lachrymal canal appears as a distinct 
ridge, arching forwards and downwards to the upper margin of the external orifice of 
the infraorbital foramen. Immediately above the infraorbital foramen there is a small 
deep lachrymal pit, which also occurs in a less-marked degree in Hrinaceus, but is not 
observed in Zupaia. The infraorbital foramen is separated from this pit by a thin plate 
of bone. It is a large opening leading into a wide and moderately long canal, that 
opens by a large orifice immediately above the interior fang of the fourth premolar. 
To return to the base of the skull (fig. 2), the mesopterygoid fossa terminates in a 
true excavation, but not of the same marked character as in Erinaceus. In Hylomys the 
tympanic bulle are more posteriorly divergent than in Hrinaceus, and in this they more 
approach Tupaia; but the area between them is excavated into two shallow, elongated, 
oval troughs lying side by side at the extremity of the basisphenoid, but separated from 
each other by a well-marked, low, sharp, longitudinal ridge, and defined on the sides by 
the expansions of the basisphenoid, which go to assist in the formation of the tympanic 
bullae. At the base of these processes there are one or two small foramina. The 
glenoid surface is nearly flat externally, but slightly concave internally. ‘The condyles 
of the occipital are divided, or nearly so, into two articular facets, of which the lower 
is almost circular; but the skulls do not appear to be young. ‘There is a rather large 
precondyloid foramen on each side, immediately below the condylar constriction; and 
anterior to it is a jugular foramen. There is a well-marked paroccipital process, 
anterior to which are two rather obscure processes in the mastoid region, and behind 
the glenoid surface a postglenoid foramen, but no process. The tympanic is ring-like ; 
but there is a vacuity between it and the tympanic process of the basisphenoid, and its 
anterior extremity is anchylosed to the process of the alisphenoid immediately below 
the foramen ovale, which is enclosed by the last-mentioned bone. 
The mandible is proportionally shorter than that of Tupaia, and in general form it 
