J ECHINOIDEA. II. 



pedicellariEe). The same kinds of pedicellaria^ occur as in Sp. purpurms, only the ophicephalous and 

 o-lobiferous forms have not been found, but it can scarcely be doubted that they occur in this species 

 too, at any rate in quite young specimens. The long and slender form of tridentate pedicellarise figured 

 bv Doderlein I have not seen; on the other hand I have found a form, which differs rather much 

 from those of purpurcus (PI. XVI. Fig. 28). They are short and rather broad, with faintly serrate edge 

 and some meshwork in the bottom of the blade; a median dorsal keel is slightly developed, the basal 

 part is wide, and the apophysis not very prominent. In larger specimens of this kind (up to i">™ length 

 of head) the valves are apart in the lower half of their length; small specimens have simply leaf- 

 shaped valves and are like those of pit-rpiircus. The second form of tridentate pedicellarise (PI. XVL 

 Figs. 17, 23) resembles that of purpureus very much, only the outer edge of the basal part is generally 

 somewhat serrate; as in purpurcus the valves may be rather elongate, thus resembling more the slen- 

 der form. A rather extreme case of this form is shown in Doderlein' s Fig. 2. a; I have not seen 

 such elongate specimens. The triph)-llous pedicellarice are like those of purpureus; the stalk of the 

 pedicellarise as in that species. 



The tube-feet and their spicules do not differ from those of purpurais. No spicules are found 

 in the walls of the intestine and genital organs. A small difference from purpuretis is found in the 

 terminal portion of the spines of the actinal plastron ; in Raschi the widened terminal portion is rather broad, 

 but short, whereas in purpureus it is little broader than the spine itself but occupying a larger portion of 

 the spine. The edges of this terminal widening are generally serrate in purpureits, smooth in Raschi. 



One specimen was taken by the Ingolf -Expedition at Stat. 55 (63° 33' Lat. N., 15° 02' Long. W. 

 316 fathoms; bottom temperature 5°9). Further I have myself dredged a specimen at the Faroe Islands, 

 (East of Sudero, 150 fathoms). 3 specimens were taken at 61° 7' Lat. N., 9° 30' Long. W. 835 M. 1904. 



This species is a decided warm-area form. The Norwegian North Sea-Exped. has dredged it at 

 several places with a bottom temperature of about 6° — with one remarkable exception : St. 96, where 

 the temperature was only — i-i; also the depth of this .station (805 fathoms) is remarkably greater than 

 where this species has elsewhere been taken (ca. 100—500 fathoms). Otherwise this case is quite ana- 

 logous to what is recorded for Echinus Alexandri. Both species undoubtedly belong to the warm area, 

 but may thus occasionally occur in places with negative bottom temperature, probably only on the 

 edge of the warm area, on the slope towards the great cold basin of the Norwegian Sea. 



The geographical distribution of Spat. Raschi is in the whole North Atlantic from Norway to 

 the Azores, but not on the American side. It is further stated in the (<Challenger>>-Echinoidea to occur 

 at the Cape of Good Hope, and recently Professor P. ell likewise mentions this species from the vSouth 

 African Sea (Echinoderma of South Africa. I. Echinoidea. p. 173). Professor Doderlein, however, sug- 

 gests that these specimens will prove to belong to the species S. capcnsis, described by him. I ha\-e 

 examined these specimens in the British Museum, and can thus state that they are really i". capcnsis. 

 Thus .S'. Raschi is not known from the South African Sea. 



Bell (69) mentions some specimens intermediate between the typical purpurcus and Raschi, 

 and lie finds it reasonable that the two species may form hybrids. I think he is right in suggesting 

 that. Figures are here given (PI. II. P'igs. 12, 14, 16) of a specimen from the F'aroe Islands (13 Miles W. 

 to S. of «Munken:', ca. 150 fathoms) which would on account of the high shape of the test decidedly 



