2 . ECHINOIDEA. I. 



canaliculata Ag. (to which Cidaris inttrix W. Th., Gonioc. vivipara Studer, and G. membranipora Studer 

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

 Hutton, and Mortenseni Koehler. Types of this genus are the species gcranioides and fubaria, espe- 

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

 almost globular pedicellaria. These pedicellarise 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 pedicellarise have a powerful end-tooth; no tridentate pedicel- 

 larise seem to be found. Spicules of the common form. There can be no doubt that G. gcranioides 

 has the same structure of the pedicellarise as G. tubaria\ the large globiferous 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. umbraculum Hutton. The pedi- 

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

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

 Doderlein, in what way the small globiferous pedicellarise 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 Goniocidaris-s-pecies by the spines being highly widened, 

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

 indistinct; the pedicellarise 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. florigcra (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- 

 gera 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: Petalocidaris , its pedicellarise 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 Petalo- 

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

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

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



