Mecieirs — Prof. V. AinaHtzhi/ — TJte Perniiaii of Rimnia, 233 



24 metres is exposed of the lower marls. At the line where these 

 marls come together there is a series of remarkable lenticular beds 

 of sand resting in trenches eroded in the lower marls and uncon- 

 formably overlaid by the upper beds. Five of these lenticular sand 

 beds are shown in section in the steep river banks in the course 

 of the ten kilometres referred to. The particular bed excavated, 

 situated at Sokolki, was 12 metres thick in its central portion, 

 with a breadth of about 80 metres. The bed contained numerous 

 irregular, hard concretions of sand cemented with carbonate of lime, 

 and in some of these the reptilian bones were enclosed. As the 

 bank at this place was vertical, and the higher portions were even 

 ovex'hanging, the only practicable means of reaching the fossiliferous 

 lenticular deposit was by digging down to it from above, which 

 entailed much labour, and a further difficulty was caused by the fact 

 that at a depth of 1"5 m. from the surface the soil, at the end of 

 June, was frozen hard, and the small fissures and cavities were lined 

 with ice. 



JMany impressions of large fronds of Glossopteris were met with 

 in some of the sandy beds, but they broke up on exposure to the 

 air. The position of the fossiliferous concretions was discovered only 

 after several fruitless trials. Some of the concretions contained only 

 single detached bones, whilst in others all the bones of a complete 

 skeleton were embedded together. Three skeletons were found side 

 by side, evidently of predatory animals allied to Rhopalodon ; under 

 these were three, more or less imperfect, skeletons of Pai'eiasauria. 

 The sand surrounding the concretions was carefully removed and 

 the surface of each layer exposed so that the positions of the 

 skeletons could be distinguished. They appeared to be all extended 

 in the same direction as if they had been carried down and deposited 

 in the bed of a stream heavily charged with sediment. The skeletons 

 in the central portions of the lenticular deposit were heaped together 

 as if they had been buried up with silt before the flesh had 

 decomposed, whilst those nearer the margins seem to have been 

 exposed long enough for decay to have set in, so that the bones 

 became detached. 



No fewer than thirty-nine groups of concretions were discovered ; 

 about twenty of these contained complete or imperfect skeletons, 

 whilst in the others the bones were detached and commingled 

 together. These concretions have not as yet been properly 

 examined, and their contents are but partially known. Of the 

 remains of Amphibians, there are skulls and other bones of forms 

 allied to Melanerpeton and Metopias. 



Both in numbers and importance the reptilian remains form the 

 chief part of the collection. They nearly all belong to the 

 Theromorpha, and the three suborders, Anomodontia, Pareiasauria, 

 and Deuterosauria, are represented. The Pareiasauria are the most 

 abundant ; amongst them are some small forms with skulls not more 

 than 30 centimetres in length, whilst others are 4-5 metres long 

 with skulls 1 m. in length and 0-G6 m. in width. Some have their 

 beads and part of their backs covered with shield-shaped plates, like 



