Reports and Proceedings — Geological Society of London. 569 



Instituto Geografico Argentina, which will contain a full description 

 of these "Cretaceous" Mammalia. 



What is befoi-e us for the present certainly shows that the fauna 

 of the Pyrotherium-hed» possesses a somewhat more archaic facies 

 than the one from the Santa Cruz beds. This is especially seen in 

 the teeth, which throughout the groups are no more rootless, but 

 have long roots with comparatively short crowns. But, apart from 

 this, all the forms appear to be still so much specialized, that the 

 author will probably stand alone in assigning this fauna to the 

 Upper Cretaceous. 



One thing is certain ; we have to do with more ancient types than 

 those of the Oligocene of Europe, from which some European 

 paleeontologists- would derive the fossil Mammalia of Argentina, 

 d travers the African continent. In several forms we see an 

 approach to the Lower Eocene, Puerco fauna, of North America. 

 Notostylops, for example, has as many claims to be a primitive 

 Edentate as some of the Puerco fossils recently described by 

 Dr. Wortman. The relation to the Puerco fauna is acknowledged 

 by Seiior Ameghino himself, when assigning several forms to the 

 Phenacodontidee and Periptychidee, " the oldest representatives of 

 the Condylarthra." 



What the author's reasons are for considering the Primates of 

 these Pyrotherium-heds as the ancestors alike of extinct and recent 

 lemurs and of monkeys, cannot be seen from the paper before us. 

 What strikes us in the figures, notably of Notopithecus (p. 4), is the 

 mode of abrasion of the teeth, quite unusual for Primates, and 

 leading to the supposition that these creatures were neither 

 insectivorous nor frugivorous. 



Of Rodentia very little is said in the present lecture ; from the 

 former paper we learn that they were provided with two premolars. 

 If these Rodents are really hystricomorphous, this character alone 

 would justify us in considering them as the forerunners of the 

 Tertiary " hystricomorphous " Rodents of Europe, and not vice versa. 



The figures intercalated in the text seem to be accurate as far as 

 they go ; but they are insufficient, being mere pen-and-ink sketches, 

 such as a travelling palasontologist would sketch in his notebook. 



On the whole, this preliminary notice of the Pyrotheriiim-heda 

 fauna is just sufficient to satisfy the cui'iosity of the naturalists at 

 large, and to excite in the highest degree the curiosity of the 

 specialist. For a fuller knowledge of the characters of this fauna, 

 we have to await the publication of the promised Memoir. 



laiBiPOi^TS .A.isrjD :F's,OGjaEiiDi3:>rc3-s. 



Geological Society of London. 



The first meeting of the session 1897-8 took place on November 3, 

 1897. Dr. Henry Hicks, F.R.S., President, in the Chair. 



The President read a letter received from the Seci'etary of State 

 for the Home Department conveying Her Majesty's gracious reply 



