I, o ECHINOIDEA. II. 



pedicellariæ). The same kinds of pedicellariæ occur as in Sp. purpurriis, only the ophicephalons and 

 globiferous forms have not been foxind, bnt it can scarcely be donbted that tliey occnr in this species 

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

 bv Doderlein I have not seen; on the other hånd I have fonnd a form, which differs rather mncli 

 from those of purpureus (PL 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 purpureus. The second form of tridentate pedicellariæ (PI. XVI. 

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

 somewhat serrate; as in purpureus 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 triph3ilous pedicellariæ are like those of purpureus; the .stalk of the 

 pedicellariæ as in that species. 



The tnbe-feet and their spicnles do not differ from those of purpureus. No spicules are fonnd 

 in the walls of the intestine and genital organs. A small difference from purpureus is fonnd in the 

 terminal portion of the spines of the actiual plastron; in Rasclii the widened terminal portion is rather broad, 

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

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



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

 3i6fathoms; 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 piaces 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 Ecliinus Alexandri. Both species undoubtedly beloug to the warm area, 

 but may thus occasionally occur in piaces 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. Rasclii 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 Bell likewise mentions this species from the South 

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

 gests that these specimens will prove to beloug to the species .S", capensis, described by him. I have 

 e.xamined these specimens in the British ■\Iuseum, and can thus state tliat they are really 6'". capensis. 

 Thus S. Rasclii is not known from the South African Sea. 



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

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

 that. Figures are here given (PI. II. Figs. 12, 14, 16) of a specimen from the Faroe Islands (13 Miles W. 

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



