20 Transactions. — Zoology. 



postero-lateral edges of the foramen magnum or the occipital 

 bone near the foramen. Thirty-four per cent, rest on the 

 mastoid processes, a posterior mastoid equiUbrium being pre- 

 sent more frequently than an anterior. In a little over 20 

 per cent, the condyles project beyond the mastoids, and the 

 skull rests on them, while in a few the lateral points of con- 

 tact are one mastoid and one condyle. 



Infra-orbital Suture. — Thirty-one per cent, of the skulls 

 have this suture present on both sides. In 15 per cent, it is 

 present on one side only. In about 10 per cent, of the in- 

 stances observed it is partly obliterated. 



Lachrymal Bone. — A pronounced deviation from the or- 

 dinary type w^as observed in only one New Zealand skull. 

 The inner w'all of the orbit is, however, frequently greatly 

 broken. In the skull referred to there is no separate lachry- 

 mal on either side, the nasal process of the superior maxilla 

 being prolonged backwards to meet the os planum of the 

 ethmoid. A small space is, however, present in the lower part 

 of this suture, and this was in all probability filled during life 

 by an ossicle. The os planum is occasionally narrowed ante- 

 riorly, the shortest ethmo-lachrymal suture I have noted being 

 5mm. 



In another skull, which I believe to be Maori, though it 

 was found at the Chatham Islands, an irregularity also occurs 

 in this region. The measurements of this skull are given with 

 those of the others from the Chathams, in Table III., but the 

 lachrymal irregularity may be described here. It occurs in 

 the right orbit. In it the lachrymal bone and the os planum 

 come in contact by a mere point. Below they are separated 

 from each other by a triangular process of the orbital plate of 

 the superior maxilla, above by a triangular ossicle which arti- 

 culates along its third side with the frontal bone."'- 



SiJheno-iJtcrygoicl Foramen. — Traces of this are present in 

 nearly 50 per cent, of the skulls of my series. In one it is 

 complete on both sides ; in two more it is complete on one 

 side, and in one of these the bridge of bone which connects 

 the pterygoid plate and the spine of the sphenoid is 7imm. 

 deep. It is nearly complete in six skulls, one of these 

 having the same condition on both sides ; it is more than 

 two-thirds formed in nine more ; while in nineteen a spine 

 is to be seen projecting backwards from the posterior 

 edge of the external pterygoid plate. In those skulls which 



* For a full description of lachrymal irregularities and their mode of 

 production, see "Notes on the Varieties and Morphology of the Human 

 Lachrymal " ; Professor Macalister, Proceedings of the Royal Society, 

 1884: also, "The Orbito-maxillary-frontal Suture in Llan and the Apes, 

 with Notes on the Varieties of the Human Lachrymal Bone " ; Mr. Arthur 

 Thomson, "Journal of Anatomy and Physiologj'," vol. xxiv., 1890. 



