300 



THE VOYAGE OF H.M.S. CHALLENGER. 



The two 

 outer rad- 

 ials and 

 the first 

 two joints 

 beyond 

 each axil- 

 lary united 

 by syzygies 



Five 



cirri at 



each 



node. 



The two 

 outer rad- 

 ials and 

 the first 

 two joints 

 beyond 

 them uni- 

 ted by bi- 

 fascial arti- 

 culations. 



L 



Cirri large and 

 stout, of 

 thirty-five to 

 fifty joints. 



Rays may 



divide five 

 times.. 



Fifteen to 



twenty - five 

 cirrus -joints. 

 Eays only 

 divide tliree 

 times. Each 

 division of 

 two joints 

 united by 



syzygy. 



Genus Pentacrinus, Miller. 



Usually fifteen to eighteen inter- 

 nodal joints. The hypozygal 

 does not share in the cirrus- 

 sockets. Generally more than 

 three joints between the irre- 

 gular arm-divisions. Pinnule 

 joints have forward projecting 

 processes. 



• L asterius, Linn. 



Six to eight internodal joints. The 

 hypozygal shares in the cirrus- 

 sockets. Only two or three j oints 

 between the regular arm-divi- 



2. miilleri, Oersted. 



i 



One or two internodal joints, 



3. ?ftac?eara>M<s, Wyv. Thorns. 



Thirty-five to forty-five internodal 1 , .„ ,, „ • t„«'„„^„ 



. .■' •' > 4. wyviUe-thornsoni, Jetlreys. 



Two and three cirri alternately at successive nodes. Rays '\ 



divide three times ; each division of two joints united by |- 5.^ altemiciri-us, n. sp. 

 .syzygy. Four internodal joints. j 



Ten arms only. The third brachial a syzygy with angular \ 

 syzygial faces. First pinnule on the second brachial. ;■ 6. 

 Eight to seventeen internodal joints. ) 



iiaresianm, n. sp. 



Rays may divide three 

 times. The second 

 free brachial a syzygy. 

 Pinnule on the first 

 brachial. 



Five to seven internodal joints. ] 

 Nodal joints not enlarged, and j 

 the hypozygal sharing but little J- 7. hlaJcei, n. sp. 

 in the cirrus-sockets. Syzygial | 

 faces angular. J 



Eleven or twelve internodal joints. "^ 

 Nodal joints enlarged and pro- 

 jecting, and the hypozygal 

 grooved to receive the cirrus- 

 bases. Syzygial faces nearly , 

 plane. J 



8. decortis, Wyv. Thorns. 



1. Pentacrinus asterius, Linn., sp. (PI. XL; PL XIL figs. 15-25; PL XIII.; 

 PL XVII. figs. 7, 8). 



1761. Palmier niarin, Guettard, Memoires de Mathematique et de Physique tires des Registres de TAcademie 



Royale des Sciences, de I'ann^e MDCCLV., Paris, 1761, p. 225. 



1762. Encrinns, capite stelhdo, ramnso dichotomo. SfipHe lymtagono-equisetiformi, Ellis, Phil. Trans., 



vol. Hi. pt. i. for the year 1761, London, 1762, p. 358. 

 1766. Ms asteria, Linnaeus, Systema Naturse, ed. xii., Holmise, 1766, t. i. p. 1288. 



