THE TRIASSIC SYSTEM 351 



HybodtiSy Ceratodus, Itipteronotus, Gyrolepis, Semionotus, and 



6 .^ . 7 8 ^-^ 



Fig. 112. GROUP Or FOSSILS FROM THE ALPIXT5 TRIAS. 



1. Pseudomonotis Clarai. 



J. Xaticella costata. 



3. Tetractinella trigonella. 



5. Ptychitcs !Stu<lri. 



0. Ceratites cassianus. 



7. Trachyceras aon. 



8. Halobia rugosa. 



10. Myophoria Keferstfini. 



11. Cidaris doraata (spiiu-). 



12. Chenmitzia gradata. 



14. Arcestes tornatus. 



15. Pinacoceras Mettcmiclii. 



16. Tropitc.s sul)bulliitiis. 

 2'2. Monotis salin:i 



23. Dadocrinus gracilis. 



Saitrichthys. The ridged teeth of Ceratodus are abundant iu some 



