ECHNIOIDEA. II. 



79 



in the anibulacral plate V. b. i, but not in I. a. i. I may call attention to the fact that the abactinal plates 

 of the odd interambnlacrnm are alternating, not paired as in P. Jeffreysi, as correctly figured by A gas- 

 si z and Loven. The pedicellariae are upon the whole well figured in the * Challenger -Report, though 

 no mention is made of them in the text The forms figured there are globiferous, ophicephalous and 

 tridentate. The globiferous pedicellarise (figured in PI. XLV. Fig. 56 as a broad based, slender-pronged, 

 and hooked pedicellaria) agree rather closely with those of P. carinata. The ophicephalous pedicel- 

 larise (figured in PI. XLII. Fig. 18, XLIII. Fig. 16 and XLV. Figs. 53 54 as Clypeastroid-like pedi- 

 cellariae) differ from those of P. Jeffrey si in having more numerous teeth along the edge of the ter- 

 minal widening, and these teeth continue along the dorsal side of the widening, whereas in Jejfreysi 

 they are only found along the inner side. This feature is well shown on PI. XLV. 53. - - The pedi- 

 cellaria figured in PL XLIII. 17 is said to be a small Clypeastroid-like > (ophicephalous) pedicellaria. 

 This must, evidently, be a mistake; the long neck shows that it is no ophicephalous pedicellaria, this 

 form of pedicellarise being always devoid of a neck in the Irregular Echini. Probably it is a small 

 tridentate pedicellaria like that figured in PL XLII. 20, only with the valves opened. The tridentate 

 pedicellariae occur in two forms; probably there will be found intermediate forms as in carinata, but 

 I have not found such. The smaller form has simply leafshaped, more or less elongate valves, with 

 the apophysis continuing into the edges, (figured in PL XLII. 19 20, XLIII. 15 and XLV. 59 as large- 

 headed pedicellariae); the end-tooth is only little prominent in the larger ones. The larger form 

 (PL XLII. 17, XLV. 57 58) has very slender, narrow valves, ending in a rather short hook and with 

 the edges serrate only near the point; this is a rather large form, the head reaching a length of ca. O7 mm . 

 Regarding Pourtalcsia rosea A. Ag. it is stated in the Challenger-Echinoidea (p. 140) that the 

 tuberculation of this species, and the shape of the test, must have been very similar to that of Pour- 

 talesia ccratopyga^. In the British Musexim are preserved only the anal snout represented in PL XXII. a. 

 Figs. 3 5 and some very poor fragments connected with a genital organ; from these fragments alone 

 it is certainly impossible to judge of the shape of the test --it seems even not very likely that they 

 belong to one species. The figures given in the Challenger Ech. do not give a better proof of the 

 shape of the test; the apical area figured in PL XXII. a. Fig. 6 with the large thin plates, showing 

 distinct concentric striation, recalls much more the thin plated Cystechinus clypcatus than a species of 

 Pmirtalesia , and it still more resembles the apical system of Sternopatagus as pointed out by de 

 Meijere (Op. cit. p. 163). (I have been unable to detect the apical system among the fragments pre- 

 served in the British Museum). I want to maintain that there is no proof in the description and figures 

 given in the Challenger-Echinoidea, and neither is such proof afforded by the fragments preserved 

 in the British Museum, that the apical system figured PL XXII. a Fig. 6 really belongs to the same 

 species as that to which the anal snout figured in the same plate Figs. 3 5 belongs, and I for my 

 part think it probable that this apical system does not belong to any Pourtalesia at all, no other 

 species of this genus having a compact apical system. To be sure, Duncan states in his Revision 

 (p. 282) that the apical system of P. miranda is compact like that of P. rosea, as can most distinctly* 

 be seen on the PL XVIII. Fig. 9 of the '^Revision of Echini*. This figure, however, only shows four 

 genital openings close together - - it does not show anything of plates, especially of the posterior 

 ocular plates. Until P. miranda has been rediscovered and carefully examined we may think it probable 



