Foss/I Rejdiles. 273 



size as the 4th, and the Gth is somewhat smaller. The six well 

 developed molars measure 19 mm. Each molar is l)roader than 

 long — the 5th being 5 mm. by 3'5 mm. The root of each molar is 

 long and has a large pulp cavity. The crown is short and well 

 enamelled. At the base of the crown the enamel forms a feebly 

 thickened ridge, and from here the crown gradually tapers. In 

 all the specimens the crowns are worn down to between 2 mm. 

 and 3mm in height. As a result of the wearing the 

 dentine is exposed in every case, and surrounded by a ring of 

 enamel. There can be no doubt that there has been some degree 

 of antero-posterior movement of the jaw. 



The lower dentition is ver}' similar to the upper. There are 

 three incisors and a fair sized canine. The incisors measure 

 11*5 mm. Behind the canine is a diastema of 5 mm., and then 

 follows a series of (j or possbily 7 molars. The dental formula 

 would thus be : 



i I c I m |p 



Neither mandible is complete; but it maj' be regarded as very 

 probable from the condition of the preserved back part of the 

 dentary that there was a distinct articular, 



Sesamu lun may at present be provisionally placed with ilie 

 Theriodonts (or Ci/nodonts), but it cannot be placed near to anj- 

 of the typical forms, and may ultimately prove to be the type of 

 a new Suborder connecting Theriodonts and Mammals. The 

 family to which it belongs may be called the Sesamodoiitidte. 



Melinodon s/iniis, g.n. et sp.n. 



This genus and species is founded on the imperfect skull of a 

 small animal belonging apparently to the same family as Sesa/nodoti. 

 The animal is remarkable for iiaving had a ver}" short pointed 

 snout and very large orbits. The molar teeth, which are ver}' well 

 preserved, are seven in number, and are fairly unifoini in size. 

 The whole molar series mearures 14 mm 



In structure they resemble those of Sesaniodon, but there is 

 no thickened ridge of enamel at the base of the crown. The skull 

 probably measured 50 mm. in width at the orbits, and the orbit is 



