558 p. H. CARPENTER ON CRETACEOTJS COMATTJL^. 



In Pentacrinus and in the Comatulce the water-pores are numerous ; 

 but in Rhizocrinus there is only one in each interradius, and in 

 correspondence with them there are five open tubes depending from 

 the water-vascular ring into the coelom. These water-tubes, which 

 are more numerous in Pentacrinus and in the Comatulce, serve to 

 admit water into the ambulacral system. Wachsmuth's observations 

 render it probable that there were five in Actinocrinus as in BMzo- 

 crinus*. May one not infer from this that there were five (or 

 more) water-pores on the disk, through which water was admitted 

 into the coelom on its way to enter the ambulacral ring by the water- 

 tubes ? 



EXPLANATION OF PLATE XXIIL 



Fig. 1. Antedon incurva, n. sp., from the Upper G-reensand, Blactdown. Cen- 

 trodorsal and radial pentagon, a, from above ; 6, from beneath ; 

 c, from the side, interradial view ; d, from the side, radial view. X 6. 



2. Antedon jperforata, n. sp., from the Upper Chalk, Margate. Centro- 



dorsal. a, ventral surface ; h, dorsal surface. X 2. c, cirrhus-socket, 

 enlarged. 



3. Antedon Ltmdgreni, n. sp., from the Upper Chalk, Margate. Centro- 



dorsal and single basal, a, ventral surface ; b, dorsal surface ; c, from 

 the side. X4. 



4. Cirrhus-sockets of Antedon rugosa. 



5. Antedon striata, n. sp., from the Upper Chalk, DDrer. Centrodorsal. 



a, ventral surface; b, dorsal surface; c, from the side. x3. d, cir- 

 rhus-socket, enlarged. 



6. Antedon laticirra, n. sp., from the Chalk of Wiltshire. Centrodorsal. 



a, ventral surface ; b, dorsal surface ; c, from the side, interradial 

 view, X 6. 



« " The Oral and Apical Systems of the Echinoderms," Quart. Journ. Microsc. 

 Science, vol. xix, pp. 185, 186. 



