ECHINOIDEA. I. 



the specimen (or specimens?), which Studer has had, with young ones on the apical area, is not 

 G. membra nipora (= nutrix}, but canaliculata, and then it is scarcely from Kerguelen (comp. the fol- 

 lowing about the occurrence of these two species). When the pedicellariae are not examined -- which 

 has evidently not been done by Studer -- it is, as has been stated above, not always to be decided 

 with certainty, to which of the two species a specimen in hand belongs; this will especially hold good, 

 when, as the case has been here, the apical area is not to be seen. 



Among the rather numerous specimens of these two species exam ned by me (from Chal- 

 lenger* at British Museum), St. canaliculata was only taken at the Falkland Islands and a station near 

 those islands, Chall. st 315, St.nutrix only at Kerguelen. Some specimens from st. 150 (Chall.) near 

 Kerguelen, 150 fathoms, have pedicellariae as those of the typical St. mitrix but the spines are much 

 longer, three times the diameter of the test; perhaps it is a separate species. Wyv. Thomson (397) 

 mentions C. nutrix from Kerguelen, G. canaliculata from the Falkland Islands. In the same way 

 S tude r's G. I'ivipara (= canaliculata} is from Patagonia, his G. membranipora from Kerguelen. Thus 

 it would seem that these two species do not occur together; St. canaliculata is found at the southern 

 coasts of South America, St.nutrix at Kerguelen. Agassiz, to be sure, mentions St. canaliciilata from 

 several other localities at Kerguelen, but according to what is shown here his statement is not to be 

 relied upon. Until a definite proof of the opposite fact comes forth, I must believe that either of these 

 species has a territory of its own, as represented here. 



Among the deep-sea specimens referred by Agassiz to G. canaliculata, I have only examined 

 two from Chall. st. 156 (the South Polar Sea, 1975 fathoms). No doubt they represent another species. 

 The large globiferous pedicellariae (PI. VIII, Fig. 35) recall very much those of the Gom'octdaris-species, 

 but the small ones are like those in canaliculata and nutrix ; and thus it would seem that this species 

 must also be referred to Stereocidaris. The ground-colour is very dark, almost black; the primary 

 spines are white, the actinal ones highly indented in the edge. Perhaps it may prove to be identical 

 with <i.Porocidarisi> incerta Koehler. I have not examined the specimens from st. 147 (1600 fathoms) 

 and 153 (1675 fathoms), but that they are not identical with St. canaliculata or nutrix, which live on 

 shallow water, may be said a priori with a great deal of probability. 



Goniocidaris Mortenseni Koehler. Koehler (233 a) in his excellent description of this species 

 mentions only one form of pedicellariae with ordinairement un on deux crochets plus on moins 

 marques at the point of the valves. This statement does not give sufficiently clear information, 

 neither does the figure of a whole pedicellaria given by Koehler show the systematically important 

 structures in a sufficiently exact way. Prof. v. Be lie den has most kindly sent me a couple of speci- 

 mens for examination, so that I am able to supply the informations wanting, and assign to this 

 uncommonly fine and characteristic species its place in the system. The large globiferous pedicellariae 

 have no end-tooth; they are quite similar to those of Stereocidaris nutrix, so that I can simply refer 

 to the figures of the latter. The small globiferous pedicellarise are rather characteristic (PI. VIII, 

 Fig. 34); they have no end-tooth, and the opening is small they recall those of <.<Porocidaris incerta 

 very much. The spicules simple. Accordingly this species is no Goniocidaris, but will probably have 

 to be referred to the genus Stereocidaris, to which genus perhaps also >.<Porocidaris incerta ought to 



be referred. 



4* 



