144 



ECHINOIUEA. I. 



small piates; liere and liere a tubercle niay he fouiul oii a soiiiewliat lart^er plate. Nearest to tlie 

 anal openin<4 tlie small piates are a little leiigthened. 



The biiccal membrane commonl\' richl\- provided with large, simple fenestrated piates as in 

 Ecli. Alexandri\ those inside of the buccal piates also as in tliis species. Biliamate spicules mav be 

 fonnd in rather great number amon«; the fenestrated piates. A few of the piates oiitside of the buccal 

 piates are larger and somewhat complicate, and carry pedicellariæ. No spines on the buccal piates. 



The spines of a middle length, '/^ — 2,, of \\-^^ diameter of the test, rather strong; they are 

 largest at the ambitus, but decrease generally only little towards the apical area. The actinal prim- 

 ary spines may be truncate and flat at the point (not constantly), not irregularly widened as iu 

 licli. aaitiis. 



The pedicellariæ are generally very ntunerous, especially the ophicephalous oues. The globi- 

 feroiis ones (PI. XVIII. Figs. 2 — 3) have most frequently 2 — 3 teeth on eitlier side of the blade, some- 

 times 3 or only one on one side, two on the otlier. The basal part has often a few indentations in 

 the edge, but tliis is 110 constant feature. The stalk is rather strong aiid may at the upper end have 

 some thorns directed downward (PI. XX. P'ig. 23). The tridentate pedicellariæ (PI. XVIII. Figs. 22, 26. 

 PI. XX. Fig. 9): the valves rather broad, a little widened at the point, wliere they join; the edge is here 

 rather sinuate, in the other part it is straight, thick, and set with small teeth forming somewhat 

 irregular transverse series. There is a rather well developed mesh-work al the bottom of the blade. 

 — Together with this form is often found a smaller one (PI. XX. Fig. 9), where the blade is almost 

 qiiite flat and rather abru])tl\ truncate at the point, without mesh-work. In some speciniens onl\- this 

 foriu is found. Transitional forms between this form and the larger one are found, so tliat it cannot 

 be regarded as another kind than the larger form. — The ophicephalous (PI. XIX. Fig. 10) and the 

 triphyllous pedicellariæ (PI. XX. F'ig. 22) show ikj marked peculiarities. — The sphæridiæ (PL XIX. 

 Fig. 26) are generally somewhat grooved and tliorny ; the grooves often form rather distiuct longi- 

 tudinal series. The spicules (PI. XX. Fig. 8) are small and rather varying in form. The)- are prett\ 

 numerous in the tube feet and gills; in the skin rotiud the base of the spines some spicules are 

 geiicralh- fouud, and sometimes a few are found iu the stalks of tlie pedicellariæ (the globifer- 

 ous ones). 



The typicrd coloration is as 011 PI. III. I-'ig. 4: jjurple, white-tipped spines; the test white, 

 slightly rosy round the apical area (PI. I. Fig. 3). In some of the specimens in hånd this colour, how- 

 ever, is only slightly indicated; some are (juite white, others have onh- a slight yellowish red tint 

 ai'oiiiid the apical area or only at the base of some of the primary tubercles 011 the abactiual side. In 

 one .specimeu the test is of a fine lilac colour (PI. I. Fig. 2). 



Ingolf St. I (62'' 30' N. L. 8" 21' W. L. 142 fathoms, Sand, Shells. Bottom tenip. 7 8). i spec. 



- 47 (61° 32' - 13° 40' - 950 - Mild. - 3° I). 3 - 



— - 52 (63^ 57' - 13" 32' - 420 — ? — 7° 2). 2 — 



- -54 (63" 08' - 15° 40' - 691 - ? - 4° 2). 6 - 



This species is indigenous in the sublittoral-archibenthal zone of the northern Atlantic, botli 

 at the European and American side, as well as south of Iceland, and in the sea along Norway; it is 

 found 011 ca. 50 — 950 fathoms. The statement that it goes down to 1350 fathoms (s^Challenger - 



