GG MR. ST. GEORGE MIVART ON HEMICENTETES. [Jan. 17, 



the specimen is fully adult and the teeth even more worn than in 

 the skull with the normal dentition, these small teeth can hardly 

 belong to the milk-dentition. 



Petrodromus. — In a new specimen, in which the last molars and 

 the upper and lower anterior incisors are not in place, I have ob- 

 served the following characters : — 



There is no sagittal crest ; the petro-mastoid, which is a single bone, 

 is separate from the squamosal, which sends down a considerable 

 entoglenoid process. 



The anterior part of the auditory bulla is formed by the alisphe- 

 noid. The petrosal has a large cerebellar fossa. 



A spatulate process extends backward from the middle of the 

 hinder margin of the palate. 



A small foramen perforates a process of the parietal, which descends 

 between the alisphenoid and squamosal. 



The rhinencephalic chamber is extensive. The second upper 

 incisor has a small cusp at its base behind ; and the lower incisors 

 are bilobed *. 



In this specimen there are but six lumbar vertebrae, and the in- 

 ternal condyle of the humerus is perforated. 



Ericulus. — There is now a complete skeleton of this form in the 

 Museum of the Royal College of Surgeons ; and a plate representing 

 it is here given by the kind permission of the authorities of that 

 institution. It has 16 dorsal, 7 lumbar, 22 sacral, and about 12 caudal 

 vertebrae. The spinous process of the axis is large, but the other 

 cervical spines are quite rudimentary. The cervical transverse pro- 

 cesses are not much antero-posteriorly expanded. The dorsal spines 

 are but slightly elongated ; but those of the lumbar vertebrae are very 

 much enlarged and antero-posteriorly extended. The lumbar meta- 

 pophyses, anapophyses, and transverse processes are small ; but the 

 lumbar spines have tolerably marked hyperapophyses. There are no 

 hvpapophysial processes. The manubrium is of moderate size and 

 not keeled. The clavicles are elongated and slender. 



Thus the genera of the order Insectivora yet known amount to 24 

 in number. 



Insectivora. 



Family I. GALEormiEciD/E : Galeopitbecus. 



„ II. Macroscelidid^e : Macroscelides, Petrodromus, Bbyncbonyon. 



„ HI. Tupaiid.e: Tupaia, Ptilocercus, Hylorays. 



„ IV. Erinaceid^e : Gymnura, Erinaceus. 



„ V. Centetidjj: Centetes,Hemicentetes,Ericulus,Ecbinops,Solenodon. 



„ VI. Potamogalid/e : Potamogale. 



„ VII. Chrysochloeid^; : Cbrysochloris, Chalcocbloris. 



„ VIII. Talpidjs. 



Subfamily I. Talpina : Scalops. Scapanus, Condylura, Talpa. 

 „ II. Myogalina: Urotrichus, Myogale. 



,, IX Soricid^e : Sores. 



* As observed by Dr. Peters in bis ' Eeise nacb Mossambique,' i. Saugetbiere, 

 p. 95, tab. xxii. fig. 9. 



