ECHINOIDEA. I. 



I.M 



trotus. In our museum is found a small Echinid from Japan, received from the museum in Vienna 

 under the name of Str.intermedius; this determination is scarcely correct, but it might agree with the 

 description of chlorocenlrotus. At all events it is another species than that of de Loriol; it has four 

 pairs of pores, while Brandt gives 5 pairs. (That of de Loriol has 7 — 5 pairs). In this specimen the 

 o-lobiferous pedieellarke are as in drebachiensis; but the spicules are simple, bihamate. Nothing definite 

 can be said of Sir. chlorocentrotus, until the type specimen has been reexamined. 



To the species here mentioned, especially intermedins and cldoroccntrotus (?) has to be added 

 iSpharechinus* pulcherrimtis, of which I have received a couple of specimens from Prof. Doderlein; 

 some specimens of this species were further found among some Echinids from Japan, which Prof. 

 d'Arcy Thompson has sent me for examination. Of this species I shall give the following informa- 

 tions. A primary tubercle is found on all the ambulacral plates (as in all the preceding species and, 

 as far as I know, in all polypore species). Only four pairs of pores in each arc, as in intermedins and 

 chlorocentrotus (mentioned by Agassiz). Three ocular plates reach to the periproct. The buccal mem- 

 brane is highly pigmented, with numerous small fenestrated plates, some few of those outside the buccal 

 plates thick, with pedicellarke. The globiferous pedicellarise quite as in drobachiensis; of tridentate 

 pedicellaria; a larger form is found (PI. XX. Fig. 10), a little widened at the point and with rather 

 sinuate edge, and a smaller form, where the edge is straight or only very slightly sinuate. The other 

 pedicellariae show no peculiarities. The spicules are bihamate, not branched. 



As none of the other species referred to Strongylocentrotus — and, upon the whole, no other 

 Echinids of ^TriplechinidcB-i and <s,Echinometrad<Bt> that I know, with the exception of the Anthocidaris 

 homalostoma Ltk. mentioned below — have the same peculiar form of globiferous pedicellarise, it is 

 evident that the mentioned species form a separate group, while it is a less sure fact whether they 

 form also one genus. The species pidcherrimus, intermedins, aud chlorocentrotus (?) are distinguished 

 from the others by having simple bihamate spicules, only four pairs of pores in each arc, and by the 

 very flat form of the test; in all of them the spines are very short, the primary ones very little con- 

 spicuous, also the primary tubercles are only little conspicuous among the numerous secondary 

 tubercles arranged in horizontal series. I am most inclined to interpret these species as a particular 

 genus (they form, perhaps, even only one species), which genus, if the mentioned specimen should 

 reallv prove to be identical with Brandt's Sir. chlorocentrotus, must get the name of Strongylocentrotus. 

 The other species: drobachiensis, pur pundits, and franciscanus, would then have to form a separate 

 genus, which, if the name of Strongylocentrotus is to be restricted to the above named species, must 

 get the name of Euryechinus Verrill 1 ). As long as we have no sufficient knowledge of the species 

 that has to be called Strongylocentrotus, viz. chlorocentrotus Br., it will be most correct to call all the 

 species mentioned here Strongylocentrotus, and leave the name of Euryechinus for disposal, if it should 

 prove to be necessary to use it. 



Strongylocentrotus deprcssus (Ag). Of this species I have received a specimen from Prof. 

 Doderlein, aud another specimen I have found among the Echinids from Japan sent me for deter- 

 mination by Prof. d'Arcy Thompson. Accordingly I am able to give some informations of it, which 



1) E. A. Verrill: On the Polyps and Corals of Panama, with descriptions of new species. Proc. Boston Soc. Nat. 

 Hist X. 1S66. p. 340. 



The Ingolf-Expedition. IV. I. l6 



