HEMIASTERIDAE 231 



formed; I have found only what appears to be the first rudiment of a globiferous 

 pedicellaria. 



One of the specimens has the madreporite separated from the right anterior genital 

 plate, as was the case in the type specimen ; in all the other specimens there is no line 

 separating the madreporite from the right anterior genital. All the specimens have three 

 genital pores, the existence of four genital pores in the type specimen being evidently an 

 anomaly. 



Globiferous pedicellariae, which were hitherto only very imperfectly known in this 

 species, are found well developed. They are of a highly characteristic structure, the 

 valves terminating in a number of quite short teeth (Plate IX, fig. 27), a type not known 

 from any other species of the Amphip7ietistes-Abatus group. As for the other pedi- 

 cellariae I may refer to the description and figures given in my report on the Echinoids 

 of the Swedish South Polar Expedition. 



I must regard it as almost certain that the A. Mortenseni, Koehler, is not to be main- 

 tained as a species separate from A. Lorioli. The former being known only from a female 

 specimen, the latter from a couple of male specimens, it was of course not easy to point 

 out exactly by which characters the two species difi^ered from each other ; but Koehler 

 thinks the pedicellariae show sufficient diff'erences to prove that the two forms represent 

 diff'erent species. It is remarkable that Koehler could have reached this conclusion. 

 Only tridentate and rostrate pedicellariae were known at that time, and they are abso- 

 lutely identical. In the shape and structure of test the two " species" are exactly alike, 

 apart from the difference due to the different sexes. There only remains the question of 

 the globiferous pedicellariae. In my report on the Echinoids of the Swedish South 

 Polar Expedition (pp. 93-4) I mention having found in A. Lorioli one, very poorly pre- 

 served, globiferous pedicellaria that seemed to be of the same structure as the globi- 

 ferous pedicellariae of A. Koehler i: that is to say with the valves terminating in two long 

 teeth and thus conspicuously different from those here figured. But it is stated that 

 "the valves have in addition to the two large teeth in the point one or two shorter 

 teeth". This might indicate that they are actually different from those of the present 

 specimens. If so, the present specimens are not identical with A. Lorioli, but should be 

 referred to A. Mortenseni, since it is a fact that the globiferous pedicellariae in these 

 forms afford excellent specific characters. But until it is definitely proved that in the 

 forms described respectively as A. Lorioli and A. Mortenseni we have two different types 

 of globiferous pedicellariae, I must believe that both belong to one species, the name of 

 which must be the older, viz. A. Lorioli. I may add that I have had an opportunity of 

 examining the type of A. Mortenseni in the Paris Museum; unfortunately not a single 

 globiferous pedicellaria is left on it. 



Amphipneustes similis, n.sp. 

 (Plate IV, figs. 1-7; Plate IX, figs. 21-26) 

 St. 170. 23. ii. 27. Off Cape Bowles, Clarence Island, 342 m. i specimen. 

 St. i8o. ii.iii. 27. Schollaert Channel, Palmer Archipelago, 160-330 m. 2 specimens. 

 St. 182. 14. iii. 27. Schollaert Channel, Palmer Archipelago, 278-500 m. 3 specimens. 



