ECHINOIDEA 



259 



the sea-urchin, but remain biting the foreign organism ; such 

 detached pedicellari?e may remain aUve for at least several hours. 



Fig. 148. — ^Various forms of Pedicellarise. (From Danmark's Fauna.) 



1. Triphyllous pedicellaria of Psammech. miliaris. 2-3. Globiferous pediceUaria of 

 Ps. miliaris: 2, closed; 3, opened. 4. Ophicephalous pedicellaria of Ps.,mj7iflr!.'?. 5. Tri- 

 dentate pedicellaria of Echinus acutus. 6. Globiferous pedicellaria of Strongylocentrotus 

 drobachiensis. 1-4, •; 45 ; 5, x 12 ; 6, x 35. g, Poison gland ; h, Xeck ; k, Valves ; 

 m, Muscles ; sp. Spicules; st, Stalk. 



The pedicellarise also seize and remove small impurities, handing 

 them from one to another, until they can be dropped outside the 



Fig. 144. — Isolated valves of globiferous Pedicellarige, in side view. 



(Fromi Danmark's Fauna.) 



1. Of Psammech. miliaris. 2. Of Echinus acutus. 3. Of Strongylocentr. drobachiensis. 

 4. Spicules from tube-feet and pedicellariae of Echinus acutus. 5. Spicule from tube-foot 

 of Strongylocentr. drobachien.sis. 1, 4, and 5, x 100 ; 2 and 3, x 35. 



animal. The faeces are stated to be removed in the same 

 way ; however, the spines also play a part in this process. The 



