542 W. H. TWELTETREES OTT A NEW THEETODONT REPTILE. 



incisor in form as well as position, are inserted in separate sockets, 

 which, together with the contained roots, taper to a more or less 

 blunt but closed extremity. 



m 1 is the root immediately behind the canine, from which it is 

 not divided by any appreciable interspace. It is the longest molar 

 root preserved. 



m 2 & 3 are smaller and more slender roots exhibiting the 

 elongated pulp-cavity, pointed extremity and closed sockets very 

 decisively. Much the same may be said of m 4. 



m 5 is the first we come to showing its crown, which was trans- 

 versely broken in treating the fossil. It is small, subconical and 

 directed backwards. Its anterior contour, which describes the greatest 

 convex curve, is sharply serrated. Its root rises perpendicularly 

 into a narrow socket, narrowing as it ascends. 



m 6 is a larger molar, also exposing part of its crown, which seems 

 to be of the same general shape and to have the same serration as 

 that of m 5, but it is more swollen. Viewing the longitudinal outline 

 of its root, there appears to me to be a very slight constriction or 

 tendency to the formation of a cervix dividing the crown from the 

 fang. The termination of this fang and its closed socket is less 

 acuminate than in the preceding teeth, m 7 is a root not essentially 

 different from m 6. 



m 8 presents a complete longitudinal section of root and crown 

 from the apex of the crown to the base of the fang. It evidences 

 a backward slant of the crown and, as it seems to me, a barely per- 

 ceptible constriction at the base of the latter. It exemplifies the 

 closed socket quite as clearly as the other teeth; but the root gains 

 a little in width upwards. At the base the corners are rounded off, 

 and thebase-liueis punched up a little, so as to cause a slight undu- 

 lation in the basal outline ; and this corresponds to a similar wave in 

 the basal outline of the pulp-cavity, which is large and conoidal, a 

 facsimile of the root itself. The cavity is produced as a linear 

 trace into the crown, m 9, partly preserved, resembles in form 

 m 7, and m 10 is only a fragment. 



Incisor. Canine. 

 in. in, 



Extraalveolar length (crown) '38 1*3 



From alveolar margin to end of fang (root) 1*1 



Total 2-4 



Molars. 



T 2. 3. 4. 5. 6. 7. 8. 9. la 



in. in. in. in. in. in, in. in. in. in. 



Crown -4 ... '29 



Eoot -76 41 4 -48 -46 -44 -38 -35 -35 



Total -48 -64 



I have now passed in review the teeth seriatim. They point, in my 

 opinion, to the location of the animal to which they belonged in the 

 Theriodont order. The excessive obliquity of the root of the canine 



