KONGL. SV. VET. AKADEMIENS HANDI.. BAND 19. N:0 7. 51 



It follows from the general description here given, that the subanal pedicels, even 

 In the antique form of Hemiaster, are penicillate, either totally, or, in most cases, 

 partially, semi-penicillate, that is: partly suctorial, partly sensitory, the central space 

 being occupied by a labiate elevation, and the periphery bearing clavate filaments. 

 It is therefore rather surprising to find two genera distinctly different from the rest 

 in this regard. 



Palasotropus Josephinte n. ^), which deviates so widely from the Spatangean type, 

 by its simple ambulacra, dorsally apetalous, and by the absence of branchial pedicels, 

 — of the usual form at least, — but which is still provided with at least semi-peni- 

 cillate phyllodean pedicels, presents, within the subanal fasciole, on either side, two 

 plates, 7 and 8, bearing pedicels, Pl. VIII, jig. 73, larger than the rest, but devoid of 

 the usual marginal crown of filaments, and presenting only a circular disk with a 

 waved margin, strengthened by about eight areolar, subtriangular, converging lamels. 

 In Meoma grandis and M. ventricosa a similarly exceptional structure occurs. The 

 phyllodean pedicels are normal, very strong, and rich in filaments. Within the 

 bivium they are such in I a, plates 1 and 2, in I h, plates 1, 2, 3; in V a, plates 

 1, 2, 3, in V h, plates 1 and 2. Then come, abruptly, very minute, simple pedicels, 

 each terminating in a small disk, the diameter of which is less than that of the tube. 

 It has a distinct, but thin and rather narrow margin, and within that a convex area, 

 in which are seen four or five converging lobes, leaving a small bare space in the 

 centre, and underlaid with an equal nnmber of lamels of rather coarse and open net- 

 work. The pedicels continue such in V b, as also in I a, by the plates 3, 4, 5, 6. With 

 their respective plates 7 they come behind the incomplete subanal fasciola, but remain 

 unaltered, only very sligtly larger in plates 7, 8 of V b, and 7, 8, 9 of la. — These 

 are the only two exceptions known to me, from what appears to be the general rule. 



The number of typical or modified subanal pedicels differs in the different genera, 

 and among the species of one and the same genus. If the figures given in my former 

 work, of the skeletal structure of the Spatangidaä are consulted, it will be found that 

 in all the Prymnodesmians figured, ^) Palajotropus, Micraster, Brissus, Meoma, Spatangus, 

 Brissopsis, Kleinia, Echinocardium, Plagionotus, Breynia, Maretia, Lovenia, the sixth 

 plate of I a and V b, though extended mesially so as to reach within the fasciola, 

 retains the minute pore of the simple pedicel in its place, near the outer margin and 

 outside the fasciola, while the true subanal pedicels begin in the seventh plate, their 

 large pores being transferred towards the inner end of the plate, and within the fa- 

 sciola. The same holds good in Metalia and Eupatagus, not figured there, and, in fact, 

 in every species of the Prymnodesmians hitherto examined, from which it may be 

 allowable to conclude that the same conformation is maintained in the genera Ciono- 

 brissus, Homolampas, Linopneustes, Argopatagus, of Al. Agassiz. Among the Prymna- 

 detes it is otherwise. ^) The order is even different in different species of the same 

 genus. Thus, in Schizaster fragilis and Sch. Moseleyi, the subanals begin with the se- 



1) Études, p. 17, pl. XII, fig. 105; XIII, fig. 108—113; XXXII, fig. 200. 



2) Ib., pl. XXXII, fig. 200, — XLIII, fig. 232. 



ä) Ib., p. 16, pl. XXVI, fig. 185, — XXXII, fig. 197. 



