452 



ECHINODERMS OF THE BRITISH ISLES 



interradii, 1 

 introvert, 351 



jaw, 148 



labrum, 319, 320 

 lantern of Aristotle, 261 

 lateral fasciole, 320 

 lateral plates, 146 



madreporite, 148, 257, 343 

 marginal fasciole, 320 

 marginal plates, 43 

 median rod, 153 

 meridoplacous, 341 

 meridosternoiis, 319, 320 

 mesentery, 352 

 monacanthid, 138 

 mouth-papillae, 148 

 mouth-shield, 148 



ocular plates, 256 

 oculars, 256 

 oligoporous, 256 

 ophicephalous pedicellarise, 260 

 oral interradial area, 43 

 oral pimiules, 12 

 oral primaries, 269 

 orals, 13 



papulae, 43 



papulariimi, 71 



paxillse, 43 



pectinate pedicellarise, 43 



pedicellarise, 2, 43, 258 



pentacrinoid stage, 14 



perforate tubercles, 257 



peripetalous fasciole, 320 



periproct, 257 



peristome, 257 



pinnules, 11 



plastron, 319, 320 



Polian vesicle, 3, 149, 262, 353 



polyporous, 256 



primary plates, 146, 255 



primary spines, 258 



primary tubercles, 257 



pyramid, 261 



R, r, 42 



radial shields, 146 



radials, 13 

 radii, 1 



recurrent rod, 152 

 respiratory trees, 352 

 rete mirabile, 4, 353 

 retractor muscles, 351 

 rostrate j^edicellariie, 260, 319 



sacculi, 12 



scrobicular spines, 269 

 secondary spines, 258 

 segmental apertures, 101 

 side plates, 12 

 siphon, 261 

 sphaeridia, 2, 260 

 sjjicules, 260 

 statocysts, 354 

 sternmn, 319, 320 

 Stewart's organs, 269 

 stirodont, 261 

 stone canal, 3, 262, 353 

 straight pedicellarise, 43 

 subanal fasciole, 320 

 superambulacral plates, 42 

 supradorsal membrane, 101 

 synarthry, 11 



syzygy. n 



teeth, 148, 261 

 tentacle scales, 147 

 tentacles, 12, 351 

 terminal plate, 42 

 tetradactylous pedicellarise, 281 

 Tiedemann's bodies, 160 

 tooth-papillse, 148 

 transverse rod, 153 

 tridactyle pedicellarise, 439 

 tridentate pedicellarise, 260 

 triphyllous pedicellarise, 260 

 trivium, 350 

 tubercles, 257 



valvate pedicellarise, 43 

 ventral plates, 146 

 ventrolateral plates, 57 

 vexillum, 61 

 vibratile lobes, 265 



wandering cells, 4 

 water vascular system, 2 



