GEOLOGICAL EANGE 261 



including Xodosaria, PoI/jinorpJiina, and .Pulvijiulina, 

 have been figured by the last-named author from the 

 Upper Trias and Ehsetic of the Southern Alps. 



In the topmost or passage beds of the Triassic 

 series — the Ehcetic — in England a somewhat rich 

 foraminiferal fauna was recently found by the writer, 

 in the marls, black clay, and shelly limestones of 

 Wedmore, in Somerset. The marly strata are there 

 filled with several species of StacJieia and Nodosi- 

 nella. The black clay yielded BeopJiax, Haplophrag- 

 mium, Ammodiscus, Bjdimina, and Truncatulina. 

 Two hyaline types, Nodosaria and MarginuUna, were 

 found in the limestones of the same series. 



In considering the foraminiferal facies of the 

 Jurassic system we shall note the general absence of 

 any of the larger Foraminifera, which in other for- 

 mations often play an important part in forming 

 massive limestones. In the strata which form the 

 Liassic beds the Foraminifera are for the most part 

 found distributed, sometimes in great abundance, in 

 certain zones of the marls and clays of the series ; 

 but they are usually quite microscopic and nearly 

 always in a small proportion to the bulk of the rock. 

 Many of the genera continue upwards into the Lias 

 from the Upper Palaeozoic strata, such as Ammodiscus, 

 Haj^Iojdn'df/iiiiiini, Valvulina, and Htaclteia. The most 

 noteworthy feature, however, is the great influx of 

 hyaline genera and species, the allied types of which 

 now only flourish in warm, temperate, and tropical 

 seas, such as the large GristellaricB, and the flattened 

 forms of the same genus, which also bear some 



