10 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 57. 



tinct, pointed, more or less rod-like bone, lying upon the inner side 

 of the postgienoid process of the squamosal and the back and inner 

 side of the glenoid articulation. In Tupaia it occupies a deep groove 

 at the outer base of the tympanic buUa between the bulla and the 

 base of the squamosal, just in front of the external auditory meatus, 

 and ])asses forwards and outwards projecting with a free extremity 

 towards the tip of the pterygoid plate of the sphenoid, with which 

 in the recent state it is connected by a separate and distinct liga- 

 ment. Behind, it passes under or to the inside of the delicate tym- 

 panic ring, to overlap the processus gracilis or processus foliatus of the 

 malleus. In old specimens it is doubtful if it exists as a distinct bone, 

 but has every appearance of fusing with the tym])anic ring with little 

 or no trace of the suture left. Just what its relation to the malleus 

 is in old or fuUy adult specimens I have not been able to determine 

 with certainty, but it appears to remain free. Even in the younger 

 stages it is closely connected to the processus gracilis by ligamentous 

 attachment and requires careful investigation to separate it. 



There is one other feature of the skull of Tupaia v/hich is more 

 reptilian-like than in any other mammal I have seen, and that is the 

 relatively wide separation of the exit of the seventh and eighth pairs 

 of cranial nerves as they enter the periotic. Of the two apertures, 

 that for the seventh or facial nerve is placed above and a little in 

 advance of the lower aperture, the two being separated by a ridge — 

 the falciform crest of human anatomy. The foramen for the exit of 

 the seventh nerve has a more or less oval form placed somewhat 

 obliquely, of which the anterior lower part accommodates the facial 

 and is thus the beginning of the fallopian canal, and an uijper back 

 part, the office of which I can not nov/ state. On the falciform crest 

 there is a distinct foramen which probably transmits the internal 

 auditory artery. The opening for the eighth or auditory ner\^e is 

 relatively large and at the bottom cribriform for the passage of the 

 nerve filaments. 



Other Insectivora. — ^Among the Erinaceidae I have been able to 

 find but a single example, and that of a species of Gymnura, in which 

 the jugal arch shows any extra elements in the adult stage. In all 

 of them the zygoma is fairly weU developed, but the jugal or malar 

 portion is relatively short, occupying the middle part of the arch. 

 There is but a faint indication of a postorbital process of the zygoma., 

 and no postorbital process of the frontal or parietal. In the specimen 

 referred to above (No. 114551) the jugal is divided by a longitudinal 

 suture near the middle into an upper and lovrer moiety, and having 

 about the same relations to the surrounding bones as in RhyncJiocyon. 



In Gymnura (fig. 5) the bone which has been described in Tupaia 

 as occupying a position at the junction of the tympanic with the 

 squamosal, just in advance of the external auditorv meatus, is 



