142 



ECHiNOinp;A. I. 



consists of long, thin calcareous threads connected b}- sn:all cross-beams. — Perrier') states that the 

 valves of the globiferons pedicellarise end in two hooks (situes snr le nienie plan . This is absolutely 

 wrong; I suppose he must have interpreted the edges of the poison canal as two separate teeth. The 

 tridentate pedicellarise (PL XVII. Figs. 2, 11, 22) with rather broad, not very deep blade; the outer 

 part, where the valves join, is somewhat widened and sinuate in the edge. The whole edge is serrate, 

 coarsely below, finely above, but there is only a single series of teeth, they form no transverse series 

 as in the Ec/it'/7?ts-species. The bottom of the blade is filled by a rather well developed net of meshes. 

 Tlie apophysis has 2 — 4 rather large indentations at the upper end. The \alves are rather wide apart 

 through the greater part of their length. In larger specimens tridentate pedicellarise are also found 

 on the buccal plates; they are smaller than the others, more spoon-shaped; the edge more straight, 

 and there is no mesh-work at the bottom (Fig. 2). According to Perrier (loc. cit.) the apophy.sis of 

 the tridentate jDedicellarise is <.decoupe en un nombre assez grand de dents pointues ; as stated above 

 I have only found 2 — 4 teeth. The ophicephalous pedicellarise show no marked peculiarities; the blade 

 is rather narrow, with well developed mesh-work (PI. XVII. Figs. 8, 28). The triph}-llous pedicellariae 

 (PI. XVn. Figs. 14, 25) are distinguished by the very finely rounded form of the blade. — The sphse- 

 ridise (PI. XVII. Figs. 26, 27) are quite smooth. 



The spicules in the tube feet are very few, often quite wanting. They are bihamate, very 

 small (PI. X\'II. Fig. 10); just below the sucking disk they may be a little irregular. The spicules 

 figured by Perrier as belonging to this species, no doubt belong to Strongylocentrotiis drobacliieiisis. 

 — There are no bihamate spicules in the gills or the buccal membrane, nor in the pedicellarise or in 

 the skin at the base of the spines. 



It is a small species; a specimen of a diameter of 35""" is uncommonly large. It is \ery 

 common in the Danish seas, quite down in the western part of the Baltic hut not in the eastern 

 part. Along the coasts of Norway it is common, at all events to Trondhjem; further it is found at 

 Iceland and the Faroe Islands, but not at Cireenland or North America. To the south it is fomid at 

 the coasts of Great Britain and along the Atlantic coasts of Europe quite down to Morocco. Bell 

 (Catalogue, p. 151) states that it is also found in the Mediterranean. 



It is a pronounced littoral form, often found just at the beach; but it is connuon down to 

 ca. 50 fathoms, and may be found on still greater depths. At the Faroe Islands I ha\-e taken a large 

 specimen (ju a depth of kx) fathoms; this fact, however, is a little uncertain. The locality- is a little 

 range of the sound between Nolso and 0stnses; it is not impossible that the dredge has got in on 

 more shallow water at the edge of tliis deej) hole, so that tlie animal nia\ ha\e been obtained there. 

 It prefers hard, stony bottom. 



Subfam. Echininas. 

 12. Echinus elegans Diib. Kor. 



PI. I. Figs. 2—3. V\. III. I'ii;. 4. V\. XV. I'ij;. 4. PI. XVI. Pigs. 3, 19. PI. XVIII. Fig.s. 2, 3, 22, 26. PI. XIX. Pigs. 10, 26. 



PI. XX. Figs. S, 9, 19, 22, 23. 



Synonym: Echinus Wallhi Ag. (?) 



Principal literature: I) ill) en iX: Koren: Ofvens. af Skandinavicns Echinodermer. p. 272. — 



') Recherches .sur les Pedicellaires. p. 146. PI. V. 



