i 7 8 



ECHINOIDEA. I. 



synonym of margaritaceus. The species described above as margaritaceus, will, if margaritaceus and 

 magellanicus really be identical, get the name of Sterech. diadema (Studer), in which species Slcrcch. 

 anlarcticus (Koehler) is to be included as a synonym. With regard to the geographical distribution 

 it will, I snppose, be proved that St. diadema (margaritaceus'}) only occurs in the seas round Kerguelen, 

 St. margaritaceus (magellanicus) round Patagonia -- analogous with Stcreocidaris nutrix and canali- 

 culata. The statements of diadema (under the name of margaritaceus) from Patagonia, I think will 

 have to be referred to horridus, which is, as to habitus, very similar to this species 1 ). It is still to be 

 observed that St. diadema has a distinct genital papilla. 



Sterechinus horridus (p. 102). There are 110 plates in the buccal membrane outside of the buccal 

 plates, which carry spines. The actinal primary spines are not curved. The character pointed out in 

 the diagnosis of the genus Sterechinus (p. 135), that the buccal membrane is almost or quite naked 

 outside of the buccal plates, is thus correct. 



Pseudechinus albocinctus (p. 104). One of the anal plates is somewhat larger than the others, 

 and carries a larger tubercle. No spines on the buccal plates. 



Parechinus microtnberculatus (p. 107). The type specimen of this species is the common Medi- 

 terranean form; the statement of Blaiuville that it has 6 pairs of pores in each arc, is thus incorrect. 

 Spiurrechiuus australiir (p. 117). Has a primary tubercle on all the ambulacral plates. Otherwise 

 the specimen examined by me, is so very similar to Sph. gianularis, that I should not be surprised, if 

 it proved to be this species ( — and in this case it is surely not from Australia — ); perhaps I have 

 then not seen the real Sph. australia at all. 



Strongylocentrotus intermedhts and chlorocentrotus (pp. 120 — 121). What I have hitherto regarded 

 as Sir. intermedins is not this species, but Sir. pulcherrimus (comp. my supposition expressed on p. 121 

 that pulcherrimus, intermedins, and chlorocentrotus (?) might be one species). The real intermedins, 

 which I got to know from Prof. Doderleiu, is as to habitus very similar to drobachiensis, also 

 with regard to pedicellariae and spicules, but is — according to Doderlein's (not published) examina- 

 tions ■-- distinguished from this by having a considerably larger number of plates in both areas, and 

 a rather smaller apical area than specimens of drobachiensis of the same size. At all events the two 

 species are very closely allied. 



■.Strongylocentrotus > gibbosus (p. 123). The examination of the pedicellariae of one of the type 

 specimens in Paris shows that this species is an Echiuometrid, I suppose of the genus Toxocidaris, or 

 perhaps a new genus. With the genus Loxec liinu s this species has nothing to do; the specimen (Chall. 

 st. 304), by which I referred gibbosus to this genus, is thxis wrongly determined (what I had a slight 

 impression of - - comp. the incongruity in the relation of the ocular plates mentioned loc. cit). Besides 

 the two type specimens (Expedition de la Bonite. M. Gaudichaud. 1837) two specimens are found in 



") When the remarks |above were printed, I received from the museum in Jardiii des Plantes > a specimen called 

 Ech. margaritaceus from Cape Horn, 1894 (Coll. Cotteau). As to habitus it resembles diadema, the secondary spines, however, 

 being somewhat coarser. All the ocular plates are shut off from the periproct ; distinct central plate, as in diadema. Primary 

 tubercle 011 every other ambulacral plate — somewhat indistinct towards the apical area. Primary spines round the mouth 

 curved at the point; a few spines on the buccal plates. The pedicellariae as in diadema. — Thus this specimen agrees neither 

 with diadema, horridtis, nor Neumayeri; nevertheless it seems rather irrational to interpret it as a separate species. The 

 supposition that diadema, horridus, and Neumayeri are all together only one very varying species, seems to me to be rather 

 obvious. But to decide this question a great material will be necessary. 



