i893. NOTES AND COMMENTS. 255 



almost all the crocodiles from the division of the Purbeck Beds in 

 question were dwarfs, and discussed the curious association of these 

 predaceous creatures with the well-known dwarf mammals of the 

 period. The further recognition of dwarf Dinosaurs existing at the 

 same time is thus of especial interest. All of these are land- or 

 freshwater-animals forming one fauna at one period in one and the 

 same region (present Isle of Purbeck), and it seems very difficult to 

 explain so remarkable an occurrence. The dwarfing of fishes is 

 much more comprehensible from the circumstances of their environ- 

 ment ; and it is curious to note that in one Purbeck stratum in 

 Wiltshire all the fossil fishes are diminutive representatives of types 

 that are comparatively large elsewhere. 



It is curious to note how widely distributed are some of the great 

 reptiles of the Jurassic period. The marine Ichthyosaurs, for instance, 

 have been found in most parts of the world. Remains of one species 

 were brought home by Sir E. Belcher from the islands between West 

 Cornwall and North Devon in the Arctic Regions ; and twenty years 

 ago vertebrae and paddle bones of two other species were discovered 

 by Baron Nordenskiold in Spitzbergen. Throughout Europe and 

 in North America remains are abundant ; and detached vertebras have 

 been found near Mombasa in East Africa. Other evidence of these 

 saurians has been discovered in Australia, and even in New Zealand 

 as far south as the 45th parallel of south latitude ; and now comes the 

 welcome announcement of the occurrence of an Ichthyosaur at two 

 localities in South America (\V. Dames, Zeitschr.detitsch.Geol. Gesell., 

 1893, pp. 23-33, pl- i-)- Some dorsal vertebras with associated 

 fragments from the Tithonian Formation of Cienegita, in the 

 Argentine Republic, are described by Dr. Dames as Ichtliyosaurus 

 hodenbenderi; and he records the discovery of two vertebrae and a 

 paddle bone of the same genus from the Andes of Chili. 



It is remarkable how new fossils are continually being discovered 

 even in the most thoroughly explored strata. The fossil fishes of the 

 Caithness flagstones have been diligently collected for seventy years, 

 and yet it is only during the past summer that a specimen of the 

 typically Lower Devonian genus Cephalaspis has been met with in 

 these rocks in the neighbourhood of Thurso. The fossil was described 

 by Dr. R. H. Traquair at the recent meeting of the British Association, 

 and is now in the Edinburgh Museum. A full account of it is promised 

 in a forthcoming volume of the Pyoc. Roy. Phys. Soc. Edinburgh. 



It is interesting to note that two species of Ostracoda found in 

 the Bear-River Formation (Upper Cretaceous) of Wyoming, have 

 been identified, by Professor T. Rupert Jones, with forms discovered 

 in this country — the one being Cypvis piiybeckensis, Forbes ; the other 



