24 ECHINOIDEA. I. 



canaliculata Ag. (to which Cidaris nutrix W. Th., Gonioc. vivipara Stiider, and G. mcmbranipora Studer 

 are referred as synonyms), florigcra A g., Doderleini Ag., biscrialis Doderl., clypeata Doderl., umbracitlum 

 Hutton, and Mortenscni Koehler. Types of this genus are the species geranioides and tubaria, espe- 

 cially peculiar by having rather deep pits between the plates, in each of which pits is placed an 

 almost globular pedicellaria. These pedicellariee are very peculiar, short and broad; the opening, 

 which is small and surrounded with distinct teeth, reaches to the point, so that no end-tooth is found 

 (PI. X, Fig. 20). The small globiferous pedicellariae have a powerful end-tooth ; no tridentate pedicel- 

 lariae seem to be fcmnd. Spicules of the common form. There can be no doubt that G. geranioides 

 has the same structure of the pedicellariae as G. hibaria; the large globiferotis ones are figured by 

 Agassiz (Revision PI. XXIV, 12 13), and they are obviously very similar to those of tubaria. 

 Perrier (op. cit. PI. Ill, 12) figures a small globiferous pedicellaria, but the figure gives no clear 

 information of the structure of the point; the text, however, leaves no doubt that it is built as in 

 G. tubaria. Most closely allied to these two species is no doubt G. umbraculiitn Hutton. The pedi- 

 cellarise (PI. X. Figs. 13, 21) show only little difference from those of the two mentioned species. Also 

 G. biserialis Doderl. belongs here; to be sure, it is not clear from the figures and description of 

 Doderlein, in what way the small globiferous pedicellariae are constructed, but Prof. Doderlein 

 has kindly sent me a preparation, so that I have been able to substantiate that they are built as in 

 the other species, with a powerful end-tooth (PI. IX, Fig. 10). The two species G. clypeata and mikado 

 are especially distinguished from the other Gom'ocidaris-species by the spines being highly widened, 

 and having, moreover, a peculiar basal widening; the impressions in the angles of the plates are 

 indistinct; the pedicellariae seem also to be somewhat different from those of the typical Goniocidaris- 

 species, although agreeing with them in main features (no end-tooth on the large pedicellarise , an 

 even uncommonly powerful one on the small ones). Thus there seems to be every reason to comprise 

 these species in a separate subgenus, Discocidaris , as proposed by Doderlein (114). Doderlein 

 thinks that G. florigcra must be referred to the same group, especially because it also shows the 

 basal widening on the spines, although only as a trace. It has long been doubtful to me, whether 

 the two forms figured by Agassiz as G. florigera (Chall. Ech. PI. I. Figs. 7 and 12), were really the 

 same species, and my doubt was confirmed, when I had examined the type-specimens in British 

 Museum. They are not only two different species, they will even undoubtedly have to be referred to 

 two different genera - - and moreover it appeared that among the specimens determined as G. flori- 

 gcra still a third form was hidden, which must also form a new genus. The form meant by 

 Doderlein when he places G. florigcra together with clypeata and mikado, is the one figured in 

 Fig. 12; it is this form of which the spines show traces of the basal widening. It has already been 

 mentioned above, and a new genus has been established for it: Pctalocidaris , its pedicellariae not 

 admitting it to be referred to any of the other known genera. Otherwise it is presumably most 

 closely allied to the two mentioned species. The other form , which is figured in Fig. 7 , shows no 

 basal widening on the spines, which are, upon the whole, very much different from those of Pctalo- 

 cidaris; they are highly and rather regularly thorny, evenly tapering. In none of the three specimens 

 (Chall. St. 204) I have examined, large globiferous pedicellariae were found, but only the small form, 

 which is quite similar to the small pedicellarise of Discocidaris (PI. X. Figs. 6 7); for the present 



