MONOGRAPH OF THE EXISTING CRINOIDS. 765 



Pi ATE 30. 



Lanw of Antedon. 



Fio. 1191. — Antedon bifida, young larva recently attiicbed. (After WyvlUe Thomson.) 

 1192. — Sumo, sompwhat more advanced. (After WyvlUe Thomson.) 

 1193. — Antedon bifida, pentacrinold larva Immediately after complete separation of oral 



valves, with cup closed. (After Wyville Thomson.) 

 1194. — Antedon mediterranea, larva of tenth day seen as transparent object; plates on 



fai"tlier side of body are omitted. (After Bury.) 



Plate 31. 



Larva of Antedon. 



Fio. 1195. — Antedon bifida, a pentacrinold before expansion of ventral disk with cup expanded 

 and showing arrangement of nonextensile tentacles. (After Wyville Thomson.) 



1196. — Antedon mediterranea, basal from larva of tenth day. (After Rury.) 



1197. — Same, an infrabasal from larva of same age. (After Bury.) 



1198. — One of uppermost columnals from same l.-irva with rudimentary longitudinal proc- 

 esses. (After Bury.) 



1199. — One of uppermost colunuials from larva of same species of seventh day. (After 

 Bury.) 



1200. — Infrabasal from same larva ; this would equally well represent a basal some 24 hours 

 earlier. (After Bury.) 



I'LATE 32. 



LarccB of Antedon bifida. {After Wyvnlle Thomson.) 



Fio. 1201. — Pentacriuoid larva immediately after complete separation of orals, expanded (fig. 

 1193.) 

 1202. — Portion of oral disk of same stage in state of complete expansion, seen from above. 

 1203. — Pentacrinold larva immediately before expansion of ventral disk. 



Plate 33. 



Ibarra- of .intcdon bifida. {After W. B. Carpenter.) 



Fio. 1204. — Group of pentacrinold larvae in different stages. 



1205. — Skeleton of early pentacrinold larva, from dried specimen, showing way in which 



calyx at that stage can be completely closed in by folding together of orals. 

 1206. — Skeleton of young pentacrinold larva, showing incipient development of dorsal cirri, 



and radlanal being lifted up from between radials. 



Plate 34. 



Pentacrinold larvw of various comatulidx. {After P. H. Carpenter.) 



Fig. 1207. — Crotalometra porrecta. 

 1208.— Same. 

 1209.— Same. 



12X0.— Hathrometra prolixa. 

 1211. — Olyplometra tuberosa. 

 1212. — Leptometra celtica. 

 1213. — Bathrometra prolixa. 

 1214. — 'tThaumatometra. sp. 

 1215. — TJeliomctra glaciali*. 



