766 DR. J. HECTOR ON CNEMIORN1S CALCITRANS. [Dec. 2, 



The frontal bone (11) is slightly swollen at the vertex, and de- 

 pressed between the orbits, which have strong overhanging orbital pro- 

 cesses, on which are rough, deeply impressed areas (Plate LXVII. d), 

 which probably gave attachment to a posterior excrescence of the 

 cere as in Plectopterus, these impressions being separated by a smooth 

 groove with only a faint mesial ridge. There appears to have been 

 a deep notch (d') in the upper part of the orbital border ; but, the 

 lachrymal bones having been lost, this is not very certain. The 

 width of the nasal suture is equal to the length of the attachment 

 of the lachrymals, which extends from the groove to the transverse 

 suture (g). 



The interorbital septum is complete ; and there are well-ossified 

 rhinal chambers, with very minute olfactory foramina that pro- 

 ceed direct from the cranial cavity. The roof of the orbit is flat, 

 with a very slight glandular groove. The optic foramen is at the 

 posterior and inner angle of the orbit, directly above the front of 

 the basipterygoid facet. Behind the postorbital process is a deep 

 imperforate pit. The brain-cavity extends six lines anterior to the 

 optic foramen. 



The upper mandible has all its elements completely fused ; the large 

 nostrils (Plate LXVII. fig. 1, e) occupy more than half the superior 

 sloping area, their aperture being directed outwards, forwards, and 

 upwards, rounded in front and angled behind ; and they are separated 

 by a smooth bony interspace (/), which is one fourth the width of 

 the mandible. The tip is rounded, with a tumid area for the attach- 

 ment of the horny mandible, the length of which is equal to its 

 width. Interiorly the palatal plate is flat, with deeply incurved 

 borders, notched on each side of the tip ; but it is deeply excavated 

 by a longitudinal groove (Plate LXVII. fig. 2, h) which is perforated 

 by two well-defined apertures, the one (A') large and directed up- 

 wards, and the other (h") small, directed backwards in a line with 

 the groove. The palatines are firmly united posteriorly with the 

 vomer, the upper surface of which has a slight groove to receive the 

 prsesphenoid. 



The lower mandible (Plate LXVI. fig. 2) is stout, but broad and 

 compressed in every part, the rami preserving a lamellate structure 

 throughout, and being united by a broad symphysis, the length of 

 which is equal to one fourth of the mandible, the anterior half being 

 flat and the posterior excavated. Inferiorly the punctate surface of 

 the attachment of the horny mandible covers the whole of the sym- 

 physial portion. 



Pelvis. 



This bone agrees with Professor Owen's description so far as his 

 imperfect specimen enabled him to fix its characters; but the com- 

 plete preservation of the bone obtained from the Earnscleugh Cave 

 enables me to add the following : — 



The neck of the ischium is compressed to form the inferior notch, 

 which is 9 lines in diameter, and contracted posteriorly to 5 lines. 

 The ischium then expands to 8 lines, with a concave external surface, 



