ECHINOIDEA. I. 



or not, is not mentioned; I have not been able to find any large globiferous pedicellarise in the few 

 specimens I have examined), and the same, I suppose, holds also good with regard to Phyttacanthus 

 dubia and parvispina Woods. Finally a similar form of giobiferous pedicellarise is found in Gonio- 

 cidaris florigera Ag. (Challenger-Echinoids, PI. I. Fig. 12) (PI. X, Figs. 27, 29); in the latter there is no 

 trace of a limb on the stalk. 



Do now all these species belong to one genus? Surely not. We shall first have to separate 

 Goniocidaris florigera. It has no trace of a limb on the stalk, the spines differ considerably from 

 those of all the other mentioned species, and I suppose that a closer examination will show several 

 other peculiarities. Doderlein (116) thinks it to be most nearly related to the species Goniocidaris 

 clypeata and G. mikado described by him, which species are distinguished by the spines being provided 

 with a peculiar flat widening at the base. Traces of such a widening are also found in G. florigera; 

 but the pedicellarise of this species are so different from those of the two mentioned species that their 

 being united into one genus is out of the question. It differs also from the genuine Goniocidaris-s-pecizs 

 (G.tubaria etc.) by its pedicellariae ; it must form a separate genus, for which I propose the name of 

 Petalocidaris. There can scarcely be any doubt, however, that it is closely related to Goniocidaris. 



Next Phyllacanthus imperialis must form a separate genus. It has peculiar large tridentate 

 pedicellarise , the blades of which are quite filled by a close net of meshes forming irregular longi- 

 tudinal ridges closely set with small teeth (PI. X Fig. 8); (the valve figured here, is from a smaller pedi- 

 cellaria where only two longitudinal ridges are seen). The small pedicellariae have no end-tooth 

 (PI. IX. Fig. 6). The spines are peculiar, thick, with fine longitudinal striae. Together with this species 

 Ph. dubia has no doubt to be placed - - if upon the whole it can be kept as a separate species, of 

 which I can have no decided opinion, as I have had no occasion to examine it. Also Phyllac. parvispina 

 Woods must, to judge by the figure given by Woods (443), belong here; its spines resemble very much 

 those of Ph. imperialis though Woods states them to be entirely different from any described species . 

 Also Ramsay (331 p. 45) says of this species that on the Australian south-coast it is the representative 

 of P. dubia of the North Coast. - This genus, no doubt, must keep Brandt's old name of Phylla- 

 canthus. Brandt 1 ) gives Cidarites dubia as the type of the section .Phyllacanthus, and observes that 

 to this will have to be added C. imperialis, hystrix, geranioides, and pistillaris. The three latter can in 

 no way be classed together with the two former; these two must keep the name of Phyllacanthus. 

 Desor in his Synopsis des Echinides fossiles (1855) establishes the genus Leiocidaris (p. 48), and as 

 the type of the genus he gives Cidaris imperialis. - - Thus there will be no use for the name of Leio- 

 cidaris, it will only be a synonym of Phyllacanthus. - - It will also be necessary to say some words of 

 the much used name of Rhabdocidaris by the present occasion. The genus has been established by 

 Desor (op. cit. p. 39) for fossil species; in a note is added: Parmi les especes vivantes on pourrait 

 reporter a ce genre les Cidaris tribuloides et C. imperialis, si leurs tubercules n'etaient pas completement 

 lisses. De Loriol (245) has later enlarged this genus to comprise: i) The fossil species of the genus 

 Rhabdocidaris sensu stricto, 2) the Rhabdocidaris-s^zcifts, with smooth tubercles, 3) the species of Leiocidaris 

 Desor and Dames (emend.), 4) the recent species of the genus Phyllacanthus Brandt, 5) the genus 

 Stcphanocidaris Ag. , and 6) the genus Schleinitzia Studer. Ainsi constitue, le genre Rhabdocidaris 

 !) Prodromus descriptionis animaliutii ab. H. Mertensio in orbis terrarum circumnavigatione observatorum. 1825 p. 68. 



