1042 On the genus Hexaprotodon. [Dec. 



Fig. 4 is the corresponding part of a specimen in Mr. Daw's collec- 

 tion*. It is the Hexaprotodon Sivulensis, Falc. Caut., and appears 

 to be the specimen figured by Durand, t. 4, f. 2.5, As. Res. vol. xix. 



The breadth of the muzzle at the insertion of the incisors is ten 

 inches, and of the jaw behind those teeth four inches, and the depth of 

 jaw is five inches, and the length from the front to the last molar eleven 

 inches. The four first cheek teeth are conical, single and prominent ; 

 the last molar is also composed of four prominent points but little 

 worn, indicative of the youth of the individual, but still the other cha- 

 racters of the specimen are so well marked as to leave little doubt of 

 its characterising a distinct species remarkable for the narrowness of 

 the jaw behind the muzzle. 



The incisors remain projecting nearly horizontally in front to the 

 extent of two inches, where they were broken (As. Res. t. 4, f. 2) 

 and may from this circumstance be presumed to have extended a consi- 

 derable distance farther in front than represented. They are all of the 

 same size, nearly cylindric, and about J of an inch or rather less in 

 diameter ; the enamel of the canine teeth is striated as in the hippo- 

 potamus and the posterior edge worn by detrition. 



Fig. 5 is the lower jaw of a specimen in Colonel Colvin's collection, 

 it is more complete than any of the others, but on the left side the cheek 

 teeth are removed to their sockets, as well as the canine teeth and 

 incisors. The height of this jaw is barely five inches and the breadth 

 of the muzzle ten and a half, the narrowest part of the jaw behind the 

 canine teeth five and a half, and the length from the front of the jaw to 

 the last molar is fourteen inches. The first cheek tooth alone seems to 

 present a single crown, the three next are double, and as the teeth are 

 perfect on the left side of an upper jaw in the same collection, which 

 seems to have belonged to an aged individual of the same species, we 

 can have no doubt as to the number of teeth proper to the group. In 

 this species there are seven cheek teeth, the second and third placed 

 in pairs. This appears to be the species indicated by Durand, As. 

 Res. xix. p. 57, t. 4, f. 4. 



Fig. 6 is the corresponding portion of the lower jaw of a specimen in 

 Dr. MacLoed's collection ; it differs from the preceding species in the 

 breadth of the jaw which measures over the alveolus of the incisors 

 eleven and a half inches, and at the narrowest part behind the 

 canine teeth, six inches ; except in breadth behind the incisors (fig. 4) 

 corresponds nearly with this specimen, but the difference of breadth is 

 so remarkable that we must, I think, regard the two as having belonged 

 to separate species. 



* The scale on which the figures are represented is one-fifth of natural size. 



