68 
THE VOYAGE OF H.M.S. CHALLENGER. 
the brachycephali the corresponding diameter was in one case as low as 164 mm., and it 
exceeded in only two cases 180 mm. The Stephanie diameter was usually greater than the 
asterionic, although sometimes the asterionic was wider in the same skull ; but the average 
Stephanie was markedly less than in the brachycephali. Below the parietal eminences 
the skulls were wall-sided. With three exceptions they were phsenozygous. 
Norma lateralis. — These skulls showed a continuous gentle curve from the glabella 
to the inion, and had not an abrupt descent from the obelion to the inion which char- 
acterised the brachycephalic crania above described. There was no definite sign of 
flattening from artificial pressure. The glabella and supraciliary ridges were not particu- 
larly prominent, even in the male skulls, and the frontal profile receded in them from the 
glabella. The cerebellar region of the occiput, although not horizontal, yet did not slope 
so much upwards to the inion as in the brachycephali. Many of the crania when placed 
on a plane surface rested behind on the conceptacula cerebelli, but some rested on the 
occipital condyles. The frontal longitudinal arc exceeded in eight specimens the parietal, 
but in six specimens was below it. The parietal arc was in excess of the occipital in all 
except three specimens. 
The osseous bridge of the nose was concave or concavo-convex, and sometimes so 
curved that the nostrils would doubtless have been directed downwards and forwards. 
The nasal bones varied in length from 20 to 25 mm., and in greatest breadth from 5 to 
13 mm. The nasal spine of the superior maxillae was not strongly marked. The sides 
of the nasal opening were rounded at their junction with the floor of the nose. The 
interzygomatic and intermalar diameters were greater than either the Stephanie or 
asterionic. The interzygomatic diameter approached more closely the greatest breadth 
in the parieto-squamous region than in the brachycephali from the same locality, and in 
three instances somewhat exceeded it. The mean interorbital width was 24 mm.; the 
maximum 28 mm., the minimum 20 mm. In some of the skulls the teeth had been lost, and 
some others were much worn, but there was no decay. In several of the crania obliteration 
of the sutures from age was in progress. In four specimens Wormian bones were in the 
lambdoidal suture. The os planum of the ethmoid was normal. No skull was metopic, 
and there was no subdivision of the malar bone. Faint indications were seen on the 
hard palate of the maxillo-premaxillary suture in two specimens. In one skull a deep- 
seated exostosis projected from the anterior wall of the external meatus. In B a 
spheno-pterygoid foramen was present on each side, and in W a projection from the 
sphenoidal spine approached the external pterygoid plate of the sphenoid. D had a 
paramastoid process on the left side. In several of these crania a suture extended from 
the infraorbital foramen into the floor of the orbit and infraorbital canal. 
In the lower jaws the sigmoid notches had no great depth ; the chin was not massive. 
The intergonial width was in three cases equal to the gonio-symphysial length, though in 
two it surpassed and in two was somewhat less than the latter. 
