the Marsupiulia, and are characterized by an important anatomical 

 condition, viz. the absence of an intestinum caecum. 



Genus 1. Thylacinus. 

 Incisors ^ ; canines ^J ; prsemolares ^ ; molares ^^ : = 46. 



The incisors are of equal length, and regularly arranged in the 

 segment of a circle with an interspace in the middle of the series 

 of both jaws. The external incisor on each side is the strongest. 



The laniary or canine teeth are long, strong, curved, and pointed, 

 like those of the dog tribe. 



The spurious molares are of a simple, blunt, conical form, each 

 with two roots ; the last with a small additional posterior cusp. 

 The true molares in the uppei: jaw are unequally triangular with 

 three tubercles. Those in the lower jaw are compressed, tricus- 

 pidate, the middle cusp being the longest, especially in the two last 

 molares, which resemble closely the sectorial teeth (rfews carnassiers) 

 of the Dog and Cat. The fore feet are 5-digitate, the hind feet 

 4-digitate. 



On the fore foot the middle digit is the longest, the internal one 

 or pollex the shortest, but the difference is slight. On the hind 

 foot the two middle toes are of nearly equal length and longer than 

 the two lateral toes, which are equal. All the toes are armed with 

 strong, blunt, and almost straight claws. The only known species 

 of this genus, the Thylacine (Thylacinus Harrisii, Didelphys Cyno- 

 cephalus, Harris), is a native of Van Diemen's Land, and is called 

 by the colonists the ' Hysena.' 



Genus Dasyurus. 

 Incisors ^ ; canines |^ ; prsemolares |^ ; molares t^^ : = 42. 



Tlie eight incisors of the upper jaw are of the same length and 

 simple structure, and are arranged in a regular semicircle without 

 any middle interval. The six incisors of the lower jaw are simi- 

 larly arranged but have thicker crowns than the upper ones ; the 

 canines present the same or even a greater relative development 

 than in the Thylacine. In an extinct species of Dasyurus they 

 present the same form and relative properties as in the Leopard. 

 The spurious molares have two fangs and a pointed compressed 

 triangular crown with a rudimental tubercle at the anterior and 

 posterior part of its base. The grinding surface of the true molares 

 in the upper jaw is triangular ; the first presents four sharp cusps, 

 the second and third each five, the fourth, which is the smallest, 

 only three. In the lower jaw the last molar is nearly of equal size 

 with the penultimate one, and is bristled with four cusps, the ex- 

 ternal one being the longest ; the second and third molares have 

 five cusps, three on the inner and two on the outer side ; the first 

 molar has four cusps : these are all sharply pointed in the young 

 animal, in which the tubercle of the posterior molar of the lower jaw 

 is divided into two small cusps. 



The carnivorous character of the previous dentition is most 



