ECHINOIDEA. I. 17 



There are 7 piates in the interambnlacral areas. In the ambulacral area there is a little tubercle 



alternately between each two primary tnbercles 



Oc 

 Oc 



, as in Porocidaris ptcrpurata. Tlie colour of the 



test is redbrown, and therefore the white, naked furrow of the interambnlacral areas is especially con- 

 spicuous. — Locality: The West Indies (no nearer information). Shonld this species perhaps be 

 Gray 's Cidaris annulatal 



Tretocidaris spinosa n. sp. The globiferons pedicellariæ have no snch reticnlation as those 

 of T. ainmlata^ and differ from those of T. Bartlctti by the sides forming an almost straight line from 

 the basal surface to the opening. (PI. X, Figs. 10, 11). The small globiferons pedicellariæ as in the 

 two other species (PL X, Fig. 16). On the stalk no distinct, freely projecting calcareons ridges are 

 seen, only a marked swelling. (It is, however, possible that the limb of the stalk is fonnd on other 

 sjjecimens; in the two other .species it was not found either in all the large globiferons pedicellariæ); 

 tridentate pedicellariæ were not fonnd. The spines closely grooved, rather finely thorned, widened at 

 the point, of the same length as the diameter of the test. The actinal spines smooth, not serrated, their 

 points not widened. The small spines are strongly redbrown. There is a naked median line in the 

 interambnlacral area, but it is only little conspicnons. 9 piates in the interambnlacral area; thns the 

 large spines are somewhat more nnmerons than commonly, which gives to the animal a very charac- 

 teristic appearance. The tnbercles in the ambnlacral areas as in T. anmilata. Locality : St. Helena (no 

 nearer information). 



Dorocidaris i bractcata Ag. The globiferons pedicellariæ much lengthened and narrow, with a 

 powerful hook at the end, and a rather small, triangular opening a little below the point (PI. X, 

 Fig. 18); the small pedicellariæ of the same strnctnre, tridentate ones simple. This form of pedicel- 

 lariæ is f urther fonnd in Phyllacanthus:> annulifcra (Lamk.), PI. X, Fig. 17, and Stcphanocidaris bispi- 

 nosa (Lamk.), and these species will have to be nnited into one genus, which must keep the name of 

 Stcphanocidaris. 



<.<Dorocidaris.> Rcini Doderl. The globiferous pedicellariæ are of a very pecnliar strnctnre; the 

 mouth is placed in the end of the blade, snrrounded by well marked teeth on the margin which is bent 

 a little ontward. Schnauzenåhnlich vorragend Doderlein says of the blade in this pecnliar form 

 of pedicellariæ, and it really resembles a snout to some degree. On the stalk a limb of short thorns 

 is found. The small pedicellariæ are of a qnite different strnctnre, a well developed end-tooth being 

 found here, and the large nionth sitnated below the point. This form of pedicellariæ is fonnd in a 

 series of species, viz. Cidaris affinis (PI. IX, Figs. 9, 22, 24) (which is in no way synonymous with Doro- 

 cidaris papillata., as has been commonly supposed), tribtdoides^ galapagensis — and, I suppose, also in 

 Dorocidaris panamensis Ag.; at all events this species, to judge by the figure, would seem to be most 

 nearly related to Cidaris affinis and Rcini; it is scarcely a Dorocidaris. The following species have 

 pedicellariæ of the same strnctnre, but are distinguished by having a limb of long, freely projecting 

 calcareons ridges on the stalk of the globiferous pedicellariæ: Cidaris >nctularia, Thouarsii (according 

 to Doderlein (116 p. 19) Cidaris Tliouarsii has only a short limb on the stalk; the specimens examined 

 by me have long limbs), vcrticillata and baculosa. Further has (according to the statement of Doder- 

 lein) Pliyllacanthus iwpcrialis the same kind of pedicellariæ (whether a limb is found on tht stalk 



The Ingolf-Expedition. IV. i. 3 



