1871.] MR. ST. GEORGE MIVART ON HEMICENTETES. Gl 



teriorly (as in Centetes) in any hemispherical excavation between 

 the basisphenoidal processes, which bend outwards to contribute to 

 form the auditory bullae. There is no conspicuous foramen in the 

 place of that one which in Centetes is situated in the roof of 

 the hemispherical basisphenoidal excavation. Instead of that one 

 foramen there are two minute ones towards the anterior end of the 

 inferior surface of the basisphenoid. The pterygoid region is much 

 more bullate than in Centetes. 



The foramen magnum is very large relatively, and looks almost 

 directly backwards. On each side of it is a well-developed parocci- 

 pital process, anterior to which, but separated from it by an inter- 

 space, is a small process of the squamosal ; so that there are two 

 processes on each side as in Centetes, only that the mastoid (placed 

 between them) contributes to neither, instead of to both of those 

 processes as in the last named genus. 



The small glenoid surface is hounded internally by a much smaller 

 entoglenoid process than in Centetes. The tympanic bone is a 

 mere ring. 



The praemaxilla is very small, and does not nearly meet the ante- 

 rior prolongation of the frontal as it does in Centetes. The nasals 

 are distinctly separate for more than their anterior half, but they 

 appear to anchylose together for their hindmost third. They ex- 

 tend backwards on the dorsum of the skull, about as far backwards 

 as do the maxillae. As in Centetes so in Hemicentetes, the parietals 

 form more, and the frontals less of the roof of the cranium than in 

 Erinaceus. The zygoma is wanting, only a small process extending 

 backwards and outwards behind as well as above the last molar. As 

 before said, the mastoid appears on the outer surface of the skull, 

 where it is subtriangular, with the apex upwards, and not bifur- 

 cating iuferiorly, as in Centetes. 



The mandible has its ascending ramus only very slightly concave 

 externally, its posterior margin between the condyle and the angle 

 relatively much longer and more concave than in Centetes. On the 

 other hand, the coronoid process is rather less raised relatively above 

 the condyle. The inner surface of the ascending ramus above the 

 dental foramen is much less concave. The horizontal ramus is not 

 constricted behind the last molar. The condyle is rather elongated 

 antero-posteriorly, and the distance from it to the coronoid process is 

 not quite so great as from it to the mandibular angle. The last- 

 mentioned part is flattened from above downwards, but so that it 

 presents a slight horizontal projection, not only on the inside, but 

 also on the outside of the vertical ramus. 



There is a small, rather pointed than obtuse, prominence on the 

 inferior margin of the mandible, a little distance in front of the 

 angle. This is sharper than in Centetes. 



There is a good-sized precondyloid foramen on each side, and in 

 front of it a jugular foramen ; but I have not observed a definite 

 carotid foramen. There is a venous foramen in the posterior part 

 of the squamosal, near its upper border, and a minute opening 

 behind the glenoid surface. The foramen ovale appears to be 



