PLATE 131. 



N.B. The signification of the characters is the same in all the figures (compare p. 718). 



a. Northern polar spines. 



6. Northern tropical spines. 



c. Equatorial spines. 



d. Southern tropical spines. 



e. Southern polar spines. 



QUADRILONCHIDA. 



Diam. Page 

 Fig. 1. Quadrilonche mesostaura, n. sp., x 300 777 



Fig. 2. Quadrilonche platystaura, n. sp., . . x 100 777 



Fig. 3. Xiplwptera dodecactena, n. sp., . x 200 778 



The central capsule with the central part of the skeleton. 



Fig. 4. Lonchostaurus Ufurcus, n. sp., . x 300 773 



Fig. 5. Lonchostaurus crystallinus, n. sp.,. ,x400 773 



Fig. 6. Lonchostaurus rhomboides, n. sp., x 200 772 



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

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

 shell of the Sphserocapsida. 



Fig. 7. Zyyostaurus amphithectus, n. sp., . x 300 774 



The square central capsule envelops the half skeleton. 



Fig. 8. Zygostaurus sagittalis, n. sp., x 300 775 



Fig. 9. Lithoptera tetraptera, n. sp., x 300 779 



Fig. 10. Lithoptera quadrata, n. sp., . . x 300 780 



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

 capsule. 



