MONOGRAPH OF THE EXISTING CRINOIDS. 



229 



Challenger. In 1881 he described similar plates in Stylometra spinifera, and in 

 1884 in Thalassometra lusitanica. 



In his memoir on the stalked crinoids of the Challenger expedition published 

 in 1884 Carpenter wrote that the margins of the ambulacra of the disk, arms, 



Pigs. 336-350. — Pinnules of VARions comatulids. 336. Middle pinndles of Nbometra MnLTicoLos. 

 337. Middle pinnules of Stylometra spinifeba. 338. Middle pinnules of Thalassometsa 

 pdbescbns. 339. Distal pinndles op Neouetra multicolor. 340. About the ninth pinnule of 

 Austrometra thetidis. 341. Dorsal view of genital pinnule of Austrometra thetidis. 342. 

 Distal pinnules op Compsombtra sebrata. 343. Distal pinnules op Ptilometba mDlleri. 344. 

 Distal pinnules of Ocbanometra gigantea. 345. Distal pinnule of Heliometra olacialis. 346. 

 Distal pinnules of Lampbometra gyges. 347. Distal pinnules of Himerometr.4 maetensi. 348. 

 Distal pinnules of Pbometha owstoni. 349. Distal pinnules of Amphimetra discoidea. 350. 

 Distal pinnules of Thalassometra villosa. 



and pinnules are rarely, if ever, perfectly free from any traces of calcareous 

 structures; they may take the form of simple short spicules, which are almost 

 entirely limited to the marginal lappets, or they may be forked and branching 

 spicules or rounded cribriform plates of variable size which are movable and 



