ECHINOIDEA. I. 1^7 



complicate (PI. XVI. Fig. 16), and the inmo.st ones show a radiate arrangement. There are no spines 

 on the buccal platcs; a few pedicellariæ mav be fonnd on the biiccal membrane, especially opposite 

 to the gills. 



The pedicellariæ. Tlie globiferous pedicellariæ (PI. XVIII. Figs. 6, 24) have one lateral tooth 

 on either side, sometimes two teeth on one side, one tooth on the other; the blade is almost tnbular, 

 the edges being coalesced to snch a degree, that only a series of small holes are left in the median 

 line, and one larger hole jnst below the large end-tooth. The basal jDart is very varying in form, 

 with more or less projecting onter corners or with qnite ronnded edge. The apophysis is narrow and 

 often rather irregular in the edge with a larger, oblong or rhombic hole at the npper end. The size 

 differs very mnch ; e.specially in var. Flcmiiigii qnite small pedicellariæ may be found. In var. iior- 

 vegicus nnmerons spicnles are generally fonnd in the stalk and head of the globiferons pedicellariæ 

 (also in the neck of the other pedicellariæ). The tridentate pedicellariæ (PI. XVIII. Figs. i, 5, 7). The 

 valves long, narrow, and deep; the npper end of the apophysis .spreads somewhat, and forms a little 

 mesh-work in the lower end of the blade; a few narrow cross-beams cross the inside of the blade for 

 a shorter or longer way. The edge is straight, thick, and set with nnmerons small teeth, placed in 

 transverse series (PL XXI. F'ig. 25); in the short part at the point where the valves join, the edge is 

 more or less coarsely serrate. They may be very long, np to 2'5""" (the length of the head). The 

 ophicephalons pedicellariæ (PI. XIX. Fig. 36) as well as the triphyllons ones withont any characteristic 

 pecnliarities. — The sphæridiæ (PI. XIX. Fig. 321 rather mnch grooved at the j^oint. — The spicnles 

 (PL XVIII. Fig. 14) of the conunon form, nnmerons, especially in the abactinal tnbe feet; they are also 

 fonnd in rather great nnmbers in the skin roimd the base of the spines, and even some wav ont on 

 the spines, in the gills, and in the bnccal membrane : in the gills together with the common irregnlar 

 fenestrated piates. Also in the pedicellariæ they may be fonnd, especially in var. norvrgicus. Some- 

 times a few S-shaped spicnles ma\' be fonnd among the common bihamate ones. 



Synonj^mons with this species are Echiniis rarispiniis G. O. Sars, dcpressiis G. O. Sars, and 

 microstoiiia Wyv. Thomson. The two former have already in Rev. of Ech. by Agassiz correctly 

 been referred to Ec//. nonugiciis. Of Ec/i. rarispiiius Dani eissen (iio. p. 4) sa}'S that if it be no 

 distinct species it is at all events a well-marked variety that seenis to work its wa\' np to an inde- 

 pendent .species». By the kindness of Prof. Collett I have from the nuisenm of Christiania got some 

 typical specimens of Ech. rarispiniis for examination; I can see no other thing bnt that thev are large 

 specimens of var. norvcgiciis. PL II. Fig. 2 ma}' so far be taken as an E.cli. rarispinus . , bnt there is 

 no reason to keep np this form as a special variety. Neither can I feel qnite persnaded that the 

 small specimens with the characteristic red spots (PL II. Fig. 6) may be said to be representatives of 

 a dwarfish variety degenerated by its confined life in the fjords (Danielssen loc. cit), as it is a faet 

 that it is not confined to the fjords, bnt is also fonnd in the midst of the Cattegat and Skager Rack; 

 also from the Mediterranean and from the Bay of Biscay I have seen qnite t\'pical specimens. They 

 are scarcely anything else than yonng specimens of EcJt. aciitiis. It is, however, to be observed that 

 snch small specimens of a diameter of ca. 1/2" may be sexnally ripe, as pointed ont by G. O. vSars'), 

 and as I have also snbstantiated on specimens from the Cattegat. We have no proof that these small, 



1) Forhandl, i Vidensk. Selsk. Chri.stiania. 1S72. p. 106. 



