122 ECHINOIDEA. II. 



group (except capensis\ in wliicli the apical system and vertex is decidedly posterior. Further the 

 globiferous pedicellariæ differ from those of the other species, as pointed out above. It might perhaps 

 not be unreasonable to regard the form of globiferous pedicellariæ in this species as a more primitive 

 form which has developed into the form found in the fragilis-^xo\y^. The faet that in this groujj some- 

 times pedicellariæ occur with two endteeth instead of one (PI. XIV. Fig. 24) might then perhaps be a 

 case of atavism. The central position of the apical system likewise seems to indicate that this species 

 is more primitive than \\\^ fragilis-^roxv^. — Accordingly I think it reasonable to regard this species 

 as the representative of a special group, besides the. /ragtiis- and canali/erus-gvow^. 



The question now arises, if these three or four groups must be regarded as distinct genera. 

 Gray (Cat. rec. Ech.) groups the species in nearly the same way as is here shown to be the natural 

 grouping; he regards the groups as subgenera, proposing for the canali/erus-gxou-p the name Nina, 

 for the fragilis-grow^ (to which S. gibbenilus is incorrectly referred) the name Brisaster, whereas the 

 name ScJtizaster s. str. is retained for S. (Moira) atropos. The species Philippii is referred to the genus 

 Tripyhis, which is certainly not correct (see Echinoidea of the Swedish South Polar Expedition); but 

 on the other hånd it is certainly not correct either to regard this species as a typical Schhaster, a 

 «Southern representative» of S.fragilis as is done by Agassiz (Rev. of Ech. p. 612). Fourtau (Op. cit.) 

 emphasizes that his canalifenis- and fragilis-gxoxv^ must really be considered only as groups of species 

 within the genus Schizaster, uot as sections — «et surtout je me garde bien de donuer un nom å ces 

 groupes, car ils passeraient vite å l'état de genre pour certains taxonomistes plus desireux d'obtenir 

 des coupes nouvelles que d'étudier å fond les variations d'un type^>. — Though I agree that when a 

 separate name of a group of species is proposed it will easily be made to rank as a generic name, I 

 think the present case is so distinct that it is necessary to give the groups names as subgenera — I 

 would even not be very horrified in seeing thera made genera. Otherwise Gray has, as said above, 

 alread>- given such names, viz. Nina for the canaliferus-grow^^ Brisaster for the /w_^77/.s--group. The 

 latter name is excellent and must be taken into use again; on the other hånd the name Nina, 

 which is quite without meaning, need not be used for the canaliferus-growp; this group may simply 

 be termed Shizaster s. str. — For S. Philippii the name Tripylaster n. subgen. may be proposed. 

 If the species gibbenilus and Savignyi are rightly made a separate group the name Paraster Pomel 

 will be kept by it. 



Unfortunately the name Scliizaster is perhaps not rightly assigned to this genus. The type of 

 the genus Schizaster, established by E. Agassiz in his eProdrome d'une Monogr. des Radiaires> is 

 ^. atropos, now named Moira. This name is a changing of the original name Mocra MicheHn, which 

 was preoccupied for a Crustacean. Strictly speaking Moira is the same name as Moera and ought 

 not to be used for the Echinid, which ought then to have its original name Schizaster — if not the 

 yet older name Echinocardium Gray! — In his paper in «Annals of Philosophy» 1825 Gray establishes 

 the genus Echinocardium with E. atropos as the first species. According to a strict interpretation of 

 the rules of nomenclature tlie name Echinocardiuiii ought to be used for Moira atropos etc. and 

 the names Schizaster Ag., Moera Mich. and Åfoira A. Ag. would be synonj-ms thereof. Instead of 

 Schizaster the name Ova Leske (van Phelsum) ought to be used. Gray (loc. cit.) naniing only tlie 

 species canalifcrus under this geiuus. Instead of Echinocardium in its present use a new name ought 



