MONOGEAPH OF THE EXISTING CRIXOIDS. 



277 



reduced merely to a small conical terminal button with little or no trace of the 

 hard vitreous cortical layer t\-[)ically present (figs. 372, 376, p. 299, and 404, 406, 

 p. 311); similarly, in species with very long and spiny cirri, such as those belonging 

 to the genera Asterometra, Ptilometra, Pterometra , Zenometra, Thahssometra, Cosmio- 

 metra, etc., which live attached to rocks or to calcified or cliitinous organisms where 

 no penetration by the terminal claw is possible, that organ has become, together 

 with the penultimate segment, quite insignificant, no longer performing any special 



^;;E FCTTTm Hit t tt M t » I I t I J::.! 1: 1 , 1 



DJ-UX-Li-Li 



Fig. 321. 



Fig. 322. 



^^>^TyT>.fr>>l >l>>^l>[^ |^°j^JJ_J_3_)Jjj} 



Fig. 323. 

 Figs. 321-323.— 321, -^ ctbrus fkom a specimen or Com.^tell.i nigra from the Philippine Islands \nEWXD (o) dorsallt 



AND (6) LATERALLY. 322, LATERAL VIEW OF A CIRRUS FROM A SPECIMEN OF C'APILLASTER UARI^ FROM SOUTHWESTERN JAPAN, 

 323, A CIRRUS FROM A SPECIMEN OF CAPILLASIEB MULUKADIATA FROM THE rniLIlTINE ISLANDS VIEWED (a) DORSALLY AND 

 (6) LATERALLY. 



function of its own, but serving merely to assist the dorsal spines in roughening 

 the dorsal surface of the cirri, the gripping action being effected entirely by the 

 embracing of the object of attachment without penetration (figs. 94, p. 155, and 363, 

 364, 366-368, p. 297). 



The terminal claw possesses a very dense cortical layer, vitreous in appearance, 

 which envelops a core of lesser density, resembUng the entire substance of the pre- 

 ceding segments. This cortical layer at the base is very tliin, but it gnuhially 



