NOTES ON PEDICELLARI^. 1:33 



Mr. G. J. Romanes, F.R.S., gives a probable explan- 

 ;a.tion of the use of the pedicellarise. He says : " In 

 <dinibing perpendicular or inclined surfaces of rock 

 -covered with waving sea-weed, it must be of no small 

 Advantage to the Echinus to be ]3rovided on all sides 

 with a multitude of forcejos, all mounted on movable 

 stalks, which instantaneously bring their grasping for- 

 •ceps to bear upon and seize a iDassing frond ; the frond 

 being thus arrested, the spines come to the assis- 

 tance of the pedicellarise, and both together hold 

 the Echinus to the svipport furnished by the sea- 

 weed. Moreover, the sea-weed is thus held steady 

 till the ambulacral feet have time also to establish 

 their hold on it with their sucking discs." * Lately I 

 had an opportunity of corroborating the same view, 

 having had a few specimens of Echinus sphccra in a 

 pail along with other objects. After having taken 

 the Echini out, I noticed projecting from the back 

 of a fine specimen of the nudibranch Doris tuhercu-, 

 lata a number of thin stalks fixed by the one end 

 into the skin of that animal, which stalks, on closer 

 examination, proved to be the pedicellarise that had 

 been rudely torn away from the Echinus when taken 

 from the pail. It was found that both pedicellarise 

 and suckers were similarly attached to stones and 

 other objects. I had hoped that they would remain 

 permanently attached, so that I could preserve them 

 in that state in spirits ; but after a short time both 

 pedicellarise and suckers let go their hold. Whatever 

 other purpose these pedicellarise may subserve, I 

 think there can be no doubt that they act in con- 

 junction with, or as auxiliaries to, the suckers of 

 the Echimis. 



* Jelly Fish, Star Fish, and Sea Urchins. — International Scienlitio Series), 



p. 285. 



