520 



Forty- fifth Report on the State Museum. 



extremity of the stem is bifurcate, but the terminal processes do 

 not extend beyond the ends of the crura; while in AthyRis, 



Fig. 157.— Jugum of Athyris spiriferoides. Fig. 158.— Jugum of Eumetria Verneuiliano . 



Tetractinella and Amphitomella they are continued backward 

 between the primary and secondary lamellae for about one fourth 



Fig. 159.— Loop of Tetractinella. (Bittnkr.) Fig. 160.— Loop of Amphitomella. (Bittner.) 



of a revolution. In Pexidblla the intercalary lamellae are still 

 longer; in Amphitomella, Ivayseria and Amphiclina they are 



i i'.. ioi. Loop of Pexidella. (Bittnbr.) Fig. 162.— Loop of Diploapirella. (.Bittnkr.) 



continued for the entire Length of the spiral cones thus making a 

 double spiral on each side. In Mkrista and Meristella the 



In Mkrista and 



72 



