THE ANNALS 



AND 



MAGAZINE OF NATUEAL HISTORY. 



[FIFTH SERIES.] 



No. 32. AUGUST 1880. 



XII. — On a remarkable Form of Pedicellaria, and the Func- 

 tions performed thereby ; together with General Observations 

 on the Allied Forms of this Organ in the Echinidse. By 

 W. Percy Sladen, F.L.S., F.G-.S. 



[Plates XII. & XIII.] 



The following peculiarities in the structure of certain pedi- 

 cellarias appear to have been undescribed. 



In Sphcer -echinus granulans (Lamk.) ; A. Ag., the jpedicel- 

 lario3 globiferoz * are very much larger than the other forms 

 of pedicellaria upon the same animal, and are of enormous 

 size when compared with the usual relative proportions of 

 this appendage in other species of Echini. The special fea- 



* I am unwilling to follow those writers who ignore altogether the old 

 names by which the different forms of pedicellaria? were originally de- 

 scribed,and who anglicize the colloquial French terms applied by Valentin, 

 although there can be no doubt whatever about the special form to 

 which each of Midler's terms belonged, the figures and descriptions 

 given in the ' Zoologia Danica ' being perfectly recognizable and charac- 

 teristic. The following tabulation of the original nomenclature and the 

 subsequent one used by the French savants will save much tedious 

 reference : — 



Pedicellaria, O. F. Midler (Zool. Dan.). 



0. F. Midler (1788). Valentin (1841). Perrier (1869). 



P. globifera = p. gemmiforme = p. gemmiforme. 



P. tripiiylla = p. ophicephale ou = p. ophicephale. 



buccal 



P. tridens = p. tridactyle = p. tridactyle. 



Ann. & Mag. N. Hist. Ser. 5. Vol, vi. 8 



