236 
MR. W. K. PARKER ON THE STRUCTURE AND 
ear-shaped mastoid process, not unlike, in size and form, the glenoid region of the 
squamosal close in front of it. The openings here are numerous ; inside the post¬ 
glenoid foramen and outer tympanic wall the canal for the facial nerve (VII.) is seen, 
and further backwards and outwards, behind a stunted and ossified (epihyal) ( e.hy .), 
the same nerve (VII.) escapes through the large stylomastoid foramen. Nearly oppo¬ 
site, but much further inwards the two fenestrae—fenestra ovalis and fenestra rotunda 
(. fs-o.jr .) are seen, and the large foramen lacerum posterius, or the common chink 
tor the exit of the 9th and 10th nerves (IX., X.) in front of, and further out than the 
foramen condyloideum for the 12th nerve (XII.) in the exoccipital (e.o.). 
The supraoccipital ( s.o .) can be just seen behind the foramen magnum ( fm .) ; the 
lateral and basal tracts (e.o., b.o.) are ankylosed. The condyles (oc.c.) are roughly 
pyriform, with the narrow part in front; each exoccipital grows out into a large, thick, 
down-turned paroccipital process ( p.oc .). This is unusually large and well developed 
lor one of the lower Eutheria. The whole occipital arch is distinct from the auditory 
capsules in front of it. 
The skull of the adult Microgale longicaudata. 
The skull, and indeed the whole skeleton of this small, very long-tailed Tenrec, 
resembles, very closely, that of the Common Shrew ( Sorex vulgaris, see Plate 31)* 
both in size and form. But there are very important differences between the two, and 
on the whole this dwarf kind is but little altered, except in form, from the Cen- 
tetidse of a more normal size. The snout ( al.n .) is somewhat shorter than in the 
Shrew ; it is similarly deflected. 
Investing bones of the skull of Microgale longicaudata. 
In the upper view (Plate 35, fig. 2) the sutures are largely filled up, yet their place 
is seen in various markings. There is, however, one long, almost perfect, median suture 
from the snout to the lambdoidal suture, and the coronal is only filled in below. 
The premaxillaries ( px .) are of considerable length, and are well wedged in between 
the nasals (n.) and maxillaries (mx.) above. The upper tract of the maxillaries is 
about equal to the nasal with which it is fused ; they project over the lachrymal 
(fig. 3,1.) ; the alveolar part of the maxillary is seen in the distance. The boundaries of 
the frontals (f.) can be seen above, wedging in between the nasals and maxillaries in 
front, and between the two parietals behind ; through their thin walls the ethmoid 
and its turbinal folds can be seen in the front half; the hinder half, apiculate before 
and behind, is smooth and gently convex. Swelling to a wddth one third greater than 
that of the frontals, the parietals (p.) nearly hide the lateral parts (sq., ep.). Each 
forms its own round convexity (see also fig. 5, p.), the sagittal suture lying in a 
furrow. The bracket-shaped lambdoidal sutural line has a remarkable setting of 
* See also Dobson, op. cit., Part ii., Plate 8, figs. 3-3/. 
