54 



premolars, of which the 1st, 3rd, and 4th persisted. There was 

 also one molar tooth. 



In the lower jaw, owing to the difficulty of interpreting the 

 conditions, it was not certain whether there were representatives 

 of five or six teeth in front of the premolars. Presuming there 

 were five, the large functional incisor of the adult was the 4th of 

 the series. As in the upjoer jaw, there were four premolars and 

 and one molar, the 2nd premolar not fully developing. There 

 were evidences of vestigial predecessors to the large lower incisor 

 and to pm"*. 



The following points of histological interest were noted : — 



1. The heaping up of the epithelium along the alveolar 



margins, a character often supposed to be peculiar to the 

 Ungulates. 



2. The precocious development of the enamel. 



3. The compactness of the stellate reticulum of the enamel- 



organ, 



4. The abundant evidence of blood-vessels within the enamel- 



organ, thus confirming the observations of Poulton and 

 Howes in the Rodents. The opposite opinion is usually 

 held. 



5. Some slight evidence in support of the fusion of enamel- 



organs. Such fusion has been recorded in the fishes and 

 reptiles, but not hitherto in mammals. 



The Rev. A. Miles Moss, M.A., F.Z.S., F.E.S., gave a short 

 account of his memoir on the Sphingidss of Peru, based on studies 

 of Lepidoptera, with special reference to the larvse, which he had 

 made during a three years' residence at Lima. Dr. Karl Jordan 

 had assisted him with the working out of his collections, and had 

 described the following new species of Sphingidaa : — 



Protoparce mossi Jord., sp. n. 



Similar to P. sexta cmstri Blanch. (1854). Both wings narrower 

 and more pointed. Fore wing without black streaks on the disc. 

 Antenna thinner. Genitalia quite different, approaching those 

 of P. hcmnibal Or. (1779). 



This paper will be published in th-e ' Transactions ' in due 

 course. 



Prof. J. P. Hill, D.Sc, communicated a paper by Dr. R 

 Broom, C.M.Z.S., on the Strvxcture of the Skull in Cynodont 

 Reptiles. The author, after a study of all the available material 

 contained in the British and South African Museums, gave a 

 detailed comparative account, illustrated by a series of figures, of 

 the morphology of the skull in the chief genera of the Cyno- 

 dontia, inclviding Bauria, Nythosaitrits, Cynognathus, Trirachodon, 

 Gomphognathus, Diademodort ^ Sesamodon, and Melinodon. He 

 also discussed in some detail certain peculiarities of the Mam- 

 malian skull, apparently derived from a Cynodont ancestor. 



