ECHINOIDEA. I. 151 



The apical area (PI. XVI. Fig. 6) i.s generally .somewhat raised, but otherwi.se of the coinmon 

 form; also liere sometimes two pores mav be fonnd in one genital plate, as in the figure. Onl\- 

 2 — 3 tubercles on each genital plate, one or none on the ocular piates. The periproct rather large, 

 covered by numerous small, more or less knob-shaped piates assuniing towards tlie anus a somewhat 

 lengthened form. No distinct central plate. 



The bnccal membrane with numerous fine fenestrated piates of the same form as in Ecli. 

 Alexandria sometimes also with rather many bihamate spicules. There are no spines on the buccal 

 piates, and none or very few pedicellariæ outside of these. The gills with the nsual irregular fenes- 

 trated piates and most frequently rather numerous bihamate spicules. 



The spines are long and strong, but hardly so much \-arying in length as in Ecli. Alrxandri; 

 e.xact informations of this faet cannot be given, as the spines are broken on the specimens in hånd 

 (when they are not quite rubbed away). The actinal spines are not broad and flat at the point. 



The pedicellariæ are generally not numerous, especially the tridentate and globiferous ones, 

 and as in the preceding species one or other of these forms mav be quite wanting. The globiferous 

 pedicellariæ (PI. XVIII. Fig. 16) have generally 2 — 2 lateral teeth, more rarely 3 teeth; sometimes only 

 one tooth is found on one side. Otherwise they show no constant difference from those of Ech.Alcx- 

 andri. Rather numerous cross-beams seem ahvays to be found between the edges of the blade. The 

 tridentate pedicellariæ (PL XVIII. Figs. 4, 28) are very different from those of the preceding species; 

 the blade is very long, narrow, and deep with a rather well developed s\stem of beams at the bottom. 

 The apophysis at its upper end spreads into a large perforated plate; most frequently a narrow, 

 irregular prolongation passes from it some wa}- into the blade, being placed a little deeper than the 

 plate. The edge is as usiial provided with transverse series of small teeth, perhaps a little less 

 numerous than in Ech. Alexaiidri. The valves are very wide apart, only joining for a little wa\- at 

 the point, which is a little obliquely cut off; in this part the edge is slightly simiate. The length of 

 the head up to 2'2™"'. The ophicephalous pedicellariæ chiefly of the same form as in the preceding 

 species, only the indentations being perhaps a little less developed; the peculiar lengthened form that 

 mav be found in Ech. Alexandria I have not found in this species. The triphyllous pedicellariæ 

 (PI. XX. Fig. 21) of the common form. The sphæridiæ (PI. XIX. Fig. 27) as in the preceding species, 

 but with fewer spines at the point, often quite smooth. The spicules (PL XX. Fig. 17) are prettv 

 varying in form; they are rather numerous in tube feet and gilLs, and sometimes in the buccal mem- 

 brane; at the base of the spines no spicules are found. 



I can give no information of the uatural colour of this species; all the specimens in hånd are quite 

 bleached both on the test and the spine.s. It reaches scarcely to so considerable a size as Ecli. Alexandri. 



('.Ingolf' st. 46 (61"' 32' N. L. 11^ 35' W. ly. 720 fms. Grav mud with stones. Bottom temp. 28). 8 spcms. 



3^ !)• 31 - 



fi)- 7 - 



3°o)- 3 - 



- 7° 2). 2 - 



- 3°o). 2 - 



- 3° !)• 10 - 



- 3° 3)- 26 - 



