344 



1881. The mutilated skull of the Perameles Lagotis, exhibiting the dentition. 



The carotid enters the fissure between the back-part of the basi- and ali-sphenoid, and 

 pierces the upper half of the side of the hinder fourth of the basisphenoid obliquely inwards 

 and upwards, scarcely inclining forwards : the two inner orifices are divided by a slender bar 

 of bone. 



Presented by the Zoological Society of London. 



Genus Myrmecobius. 



1882. The skeleton of the Banded Myrmecobius (Myrmecobius fasciatus). 



This genus .is remarkable for the small size, the great number, and separate implantation 

 of the teeth ; the dental formula being : i ^, c j^J, p ^, m ^5=54. From this formula 

 it will be seen that the number of molars, eighteen in both jaws, exceeds that of any other 

 known existing Marsupial, and nearly approaches the peculiar dental formula of the extinct 

 Thylacotherium, and that which characterizes some of the existing Armadillos. The resem- 

 blance to the genus Dasypus is further carried out in the small size of the molar teeth, their 

 separation from each other by slight interspaces, and their implantation in sockets, which are 

 not formed upon a well-developed alveolar ridge or process. The molars, however, present a 

 distinct multicuspidate structure, and both the true and false ones possess two or more sepa- 

 rate fangs, as in other Marsupials. The inferior molars are directed obliquely inwards, and 

 the whole dental series describes a slight sigmoid curve. The false molars present the usual 

 compressed triangular form with the apex slightly recurved, and the base more or less 

 obscurely notched before and behind. The canines are very little longer than the false 

 molars : the incisors are minute, slightly compressed and pointed ; they are separated from 

 each other and the canines by wide intervals. 



The inner condyle of the humerus is perforated. There is a sesamoid behind the outer 

 condyle of each femur. The inner toe is reduced to a rudimental metacarpal. The transverse 

 processes of the seventh as well as those of the other six cervical vertebrae are pierced by the 

 vertebral artery. 13 vertebrae are dorsal, 6 lumbar, 3 sacral, and 22 caudal, the fourth to 

 the ninth of which last have hsemapophyses. 



The Myrmecobians are insectivorous, and shelter themselves in the hollows of trees, 

 frequenting most, it is said, those situations where the Port-Jackson willow abounds. In the 

 structure and proportions of the hind feet they resemble the Dasyurine family ; in the slightly 

 developed canines, the smooth external surface of the skull, the breadth between the zygo- 

 mata, and the absence of the interparietal ridges, as well as in its general external form and 

 bushy tail, the present species offers an especial approximation to the genus Phascogale. 



Mm. Gould. 



1883. The skull of the Myrmecobius fasciatus. 



It has been longitudinally and vertically bisected. The numbers on the bones refer to 

 the TABLE OF SYNONYMS. 



Mus. Gould. 



