PLATE 131. 



N.B. — The signification of the characters is the same in all the figures 



a. Northern polar spines. 



b. Northern tropical spines. 



c. Equatorial spines. 



d. Southern tropical spines. 



e. Southern polar spines. 



(compare p. 718). 



QUADRILONCHIDA. 



Fig. 



1 



Fig. 



2 



Fig. 



3 



Fig. 



4. 



Fig. 



5 



Fig. 



6 



Fig. 7. 



Fig. 8. 

 Fig. 9. 

 Fig. 10. 



Quadrilonche mesostaura, n. sp., 



Quadrilonche platystaura, n. sp., . 



Xiphoptera dodecactena, n. sp., 



The central capsule with the central part of the skeleton. 



Lonchostaurus bifurcus, n. sp., 



Lonchostaurus crystallinus, n. sp., 



Lonchostaurus rhomboides, n. sp., 



The radial spines are completely enclosed in the rhomhic calymma, the 

 surface of which is covered with small plates, similar to those in the 

 shell of the Sphasrocapsida. 



Zygostaurus amphithectus, n. sp., 



The square central capsule envelops the half skeleton. 



Zygostaurus sagittalis, n. sp., 



Lithoptera tetraptera, n. sp., 



Liihoptera quadrata, n. sp., . 



The central part of the skeleton is enclosed by the four-lobed central 

 capsule. 





Diam. 



Page 



X 



300 



777 



X 



100 



777 



X 



200 



778 



X 



300 



773 



X 



400 



773 



X 



200 



772 



x 300 



774 



x 300 



775 



x 300 



779 



x 300 



780 



