1897.J DR. R. H. TRAQUAIR ON PAL/EOSPONDTLTJS GTJJSTS^I. 313 



but new collections -were continually being obtained by the officers of 

 the Museum, who were periodically despatched on exploring expedi- 

 tions. Among the more interesting acquisitions of 1896 were some 

 crocodilian and ophidian skeletons from the red sandstones of the 

 Territory of Neuquen, which were supposed to be of Cretaceous age, 

 and had already yielded the Dinosamnan remains lately described by 

 Mr. Lydekker. The Crocodiles (described by Mr. Woodward in 

 the ' Anal. Mus. La Plata, Paleont. Argent,,' pt. iv. 1896) were of 

 special interest as being of a Mesozoic type, with a short and 

 broad head and a terminal narial opening. Their teeth were few and 

 well difEerentiated into incisors, canines, and molars, apparently 

 without any successional teeth. The Ophidian was ii] a wonderful 

 state of preservation, but was still undescribed. The red sandstones 

 in which these reptihan remains occurred were believed to be of the 

 same age as the earliest deposits containing mammalian remains in 

 Southern Argentina. Hence the latter were usually considered to 

 date back to the Cretaceous period. 



The succession of the mammaliferous deposits of Patagonia and 

 the adjoining territories had hitherto been most thoroughly 

 investigated by Senor Carlos Ameghino, who had conducted an 

 exploring expedition each year since 1887, and had amassed an 

 enormous private collection which his brother, Dr. Plorentino 

 Ameghino, had studied with results so important and so well 

 known as not to need detailed recapitulation here. Above the red 

 sandstones of Neuquen, and below the superficial pampean deposits, 

 the brothers Ameghino now recognized two distinct mammalian 

 faunas — the older of the Pyrotherium Formation, and the later of 

 the Santa Cruz Formation, both particularly remarkable for the 

 abundance of highly specialized IJngulata. Near the coast the 

 marine Patagonian Formation fortunately separated these two fresh- 

 water or terrestrial horizons, and thus afforded a means of deter- 

 mining their age. The Cetacean remains found in the marine 

 intercalation (as had been noted by Mr. Lydekker) seemed to cor- 

 respond with those termed Miocene in the northern hemisphere ; 

 the Selachian teeth from the same formation presented by the 

 brothers Ameghino to the British Museum were also of a Miocene 

 or even early Pliocene facies. Mr. "Woodward was therefore inclined 

 to believe that the Santa Cruz fauna was not earlier than the Miocene, 

 and might even be homotaxial with the Lower Pliocene of the 

 northern hemisphere. There was no decisive evidence of any of 

 the Patagonian mammals hitherto discovered dating back to the 

 Cretaceous period. 



Dr. R. H. Traquair, F.E.S., exhibited and made remarks upon 

 a new specimen of the supposed fossil Lamprey {Palceosponclylus 

 gunni) from the Old Eed Sandstone of Caithness, and read a note 

 on its affinities (see below p. 314). 



Mr. E. T. Newton agreed with Dr. Traquair that the slight 

 markings seen on the stone near the fish-remains, which had been 



Peoc. Zooi. Soc— 1897, No. XXI. 21 



