70 



undesirable duty of signifying them by adding another specific name to the present 

 well-marked genus. 



I give my original notes on the type specimen of Tr. occisor. 



" Both rami, somewhat mutilated, of the same mandible, the left (/) showing the outer 

 side, the right (;) (good for molars) the inner side ; and the latter more complete, having 

 ;i fore-and-af< extent of coronoid process preserved for nine lines behind the last molar. 

 Part <>l" the inflected ridge or angle (a) is shown. In advance and above this is the entry 

 of the dental canal (//), the condyle itself is broken away. The longitudinal linear groove 

 is seen to terminate near the symphysis. The thicker inner alveolar plate is here well 

 contrasted with the thinner outer Avail of the sockets in /. The minutely tubercular ridge 

 along the base of the inner side of the crown is well shown in the first molar " (m 1, fig. 2 

 b) ; " also the vertical groove close to the anterior border of each cone (most clearly shown 

 in the first and second cones). The hind basal notch or talon comes well out on the 

 outer side of the left m \ and m 2 " (fig. 2 a, PI. IV). 



" The last molar is not quite in place, its hindmost cone has not emerged or come 

 forward from its alveolus, where it is exposed in the right ramus "(fig. 2,r, and 2 b, m 3). 

 " The last premolar " (p 4, fig. 2 a) " has not risen into place ; its apex is on a level with 

 the base of the first cone of m 1. The third premolar " {p 3, fig. 2 b) " is in place in 

 the right ramus, and shows the basal ridge along its inner side, together with the large 

 posterior talon ; the anterior talon is feebly indicated. 



" Both anterior and posterior talons are more conspicuous and more equal in the second 

 premolar " (fig. 2 b,/? 2), " which is much smaller than the third, chiefly through the minor 

 development of the main cone, which is less acute than that of p 3. The first premolar 

 {p 1) has a still smaller main cone with an anterior and a posterior cusp. The premolars, 

 like the molars, are inserted each by two roots." 



So much of the crown of the canine as has risen into place shows a less recurved shape 

 than in Triconodon ferox. The anterior border of the jaw rises at an open angle with the 

 lower one to the incisive alveoli, as in Triconodon mordax. It does not ascend or curve 

 gradually up as in Triconodon ferox. 



Species 4. — Triconodon major, Ow. Plate IV, fig. 3. 



In a block of stone, from the part of the Middle Purbeck marked ' Feather,' in fig. 4, 

 p. 22, the stone being similar in character with that containing the Swanage Crocodile 

 (Goniop/wlis), Turtles (Pleurosternon, &c.) and Fish [Microdus, &c), and which the 

 masons were sawing up, their attention was caught by the appearance of a fossil in the 

 line of section. The process was stopped, and the portion of stone with the fossil cut 

 out. It was purchased for the British Museum, and, after careful development of the 



