lO 



ECHINOIDEA. I. 



are perfectly recognisable, and therefore his names onght to be restored to their rights. The name of 

 P. triphylla of Miiller, however, no doubt includes as well ophicephalous pedicellarise as triphyllous 

 ones. This name must then be kept for the small form the valves of which resemble clover-leaves, 

 while Valentin's name P. ophicephale is kept for the form described by him under this name. — 

 Hamann (184) uses the name < Globiferen > especially of the pedicellarise where the mucous glands on 

 the stalk have been so highly developed, that the head has become rudimentary or is e\-en quite 

 wanting. Thus they, as is also admitted by Hamann himself, are not a peculiar kind of organs, 

 but only transformed pedicellarise; it may, jDerhap.s, be as well to have a special name for these pedi- 

 cellarise, but the name of (Globiferse> cannot be restricted to them, as has also been observed by 

 Duncan (130). It is, in realit>', contrary- to all common practice not to use the names of Miiller. 

 The reason for keeping Valentin's names given by Geddes and Beddard (163): both on account 

 of their general acceptance and because they were the first names applied to pedicellarise after the 

 determination of their real nature; M tiller's nomenclature refers to pedicellarise as a genus of para- 

 sitic animals , is not sufficient for a disregarding of the common rules of priorit}-. Accordingly the 

 names that ought to be used, are the following: 



Globiferous pedicellaria; — Pcdiccllaria globifcra Miiller 



Tridentate 



Ophicephalous 

 Triphyllous 



^ — — tridens 



opliioccf>Jiala Valentin 

 triphylla Miiller 



Pedic. gemmiforme \'alentin, Perrier. 



P. arme Perrier (in the Cidarids). 



(Globiferen Hamann. 

 ( P. tridactyle Valentin etc. 

 I P. inerme Perrier (in the Cidarids). 

 ( P. triphylla Miiller pro parte. 

 I P. buccale Valentin, Hamann. 



P. trifolie Perrier. 



To facilitate the understanding of the descriptions in the following, figures are anue.Ked 

 showing a single valve of each of the four kinds of pedicellarise together with the names used for 

 the separate jjarts. 



To be able to study the pedicellarise, especially the calcareous skeleton , which is of jjarticular 

 importance for the classification, the\' nuist necessarily be treated carefully. On being boiled in 

 a not too strong solution of potash the separate pieces of the skeleton may easily be isolated, and no 

 very great technical skill is necessary to be able to make preparations in Canada balsam of these 

 pieces. (They cannot be kept in glycerine, as it resolves the lime). Accordingly I can in no way 

 subscribe to the opinion of Pom el that the pedicellarite only with difficulty can be used for the 

 classification, because < leur tenuite en rend I'etude pen pratique (324 p. 13). 



Also the spicules yield good systematic characters, even if they are not, in this respect, equal to 

 the pedicellarise. They only rarely \ield specific characters, and are oftenest very similar in the sepa- 

 rate genera of the same famih-, but they may yield excellent famil\- character.s. Tlie\ ma\' l)e 

 of a .simple C-shape (<bihamate>) — the most comiudii form — or a little branched in l)oth ends 

 (Sirongylocentrohcs), or pointed in both cuds, and with one branch or a couple of snuill branches in 

 the middle, <biacerate) (Parasalenia, A)ithocidaris)\ in SplicrrccJtiinis and especially in Toxopiiciistcs and 



