214 HISTORICAL PALAEONTOLOGY. 



characters, but would appear to be mostly nearly related to the 

 recent Cypresses. 



As regards the Invertebrate animals of the Trias, our knowl- 

 edge is still principally derived from the calcareous beds 

 which constitute the center of the system (the Muschelkalk) 

 on the continent of Europe, and from the St. Cassian and 

 Rhsetic beds still higher in the series; whilst some of the 



Fig. 141 Triassic Conifers and Cycads. a, Vollzia (Sckizoneura) heterophylla , 

 portion of a branch, Europe and America ; ft, Part of the frond of Pterophyllum 

 Jwgeri, Europe j c, Part of the frond of Podozamites lanceolatus, America. 



Triassic strata of California and Nevada have likewise yielded 

 numerous remains of marine Invertebrates. The Protozoans 

 are represented by Foraminifera and Sponges, and the Ccelen- 

 terates by a small number of Corals; but these require no 

 special notice. It may be mentioned, however, that the great 



