﻿118 



MURIE 



ON THE THREE-BANDED ARMADILLO 



Regard 



on 



no' ihe exterior configuration of the cranium of Toltjpeutes, Turner, Owen, 

 and gTcM have demonstrated its salient characters, to which I shaU only add remarks 

 the tympanic region, for reasons afterwards to be specified. Those authors justly 

 dlude to the laminar, imperfect annular nature of the tympanic, and its differing, there- 

 fore from that of certain other Armadillo genera. 



In T, conurus I find the tympanic to be f of a circle (0-25 mch m diameter), deeply 

 ed on its inner aspect for the reception of the membrana tympani. It is fastened 

 behind to a circumscribed ledge at the fore part of the descending mastoidal element, and, 

 whHe partially free in circumference, impinges anteriorly and above upon the broad end 

 of the malleus : the latter nearly completes the 



srroo; 



In the recess at the back 



of the jaw-articulation a postglenoid foramen leads into the cranial diploe above, a 

 secondary communication opening outside behind the root of the zygoma. At the fore 

 margin of the tympanic, and between it and the glenoid surface, is a considerable-sized 

 oblique opening, with downwardly continued bony groove, which I apprehend to be 

 the Eustachian foramen ; for alongside and immediately beneath is a cleft, converted 

 into a tunnel by membrane &c., answering best to the fissura Glaseri. Inward from 

 these is the carotid orifice, all but continuous with the foramen lacerumposterius. Below 

 the tympanic plate a roughened exostosis on the petrosal is apparent ; and on removal 

 of the tympanic and auditory ossicles this so-called tympanohyal becomes 



ous. The cochlear prominence is moderate, partly hiding the fenestra rotunda, the 



diameter of this aperture being obliquely towards the anterior condyloid foramen. 



The fenestra ovalis is situate O'l inch hiorher. The names of these fenestrae are reversely 



more 



spu 



:i ppropriatc as regards shape ; and the latter is the smaller of the two. Encompassing 

 them rearwards is a well-marked furrow, apparently equivalent to the aqueduct of 

 Fallopius, overarching which is the mastoidal segment. This barely evinces trace of 

 n styloid process, the narrow ledge in its position supporting the tympanic as aforesaid. 

 Above, and close by, however, is a stylo-mastoid foramen ; behind, a short nipple- 

 shaped mastoid process, posterior and at the root of which a large mastoid foramen 

 obtains. 



Of the small car-bones, the malleus has an expanded trihedral base, tenuous centrally, 

 and thicker at the margins ; that on the right side in this specimen possessed an outward 



return 



Osteological Catalogu 



a 



le/ I am not aware of their having been published in a separate paper; 



)y they are likely to escape the notice of writers^ I here append them m 

 nowhat connected form. Affixed to the quotations are the numbers of the specimens in the said vol. ii,, transposed, 

 Bver, to the regional distribution of the bones, and not numerically consecutive. 



The tyrnpanic is a distinct lamina of bone bent in a half circle ; the membrane connecting its inner and under 

 with the lower part of the petrosal is not ossiBed so as to form a continuous tympanic buUa as in the 



pruoon. There is i 

 orbit. The alisphen 

 cnpsule. There axe 



usual 



The lachrymal is large, and forms a triangular plate upon the face outside the 



maiiUaries, and the same number on each side of the lower jaw ^' (2307) 



:illary 





