

KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 58. N:0 9. 5 



Nothing can be said of the character of the peristome, only a very small frag- 

 ment of it being left in specimen b. 



The large globiferous pedicellariae appear to be numerous on the peristome; 

 there are several of them on the few peristomial plates left in specimen b. They 

 differ somewhat from those of Ph. imperialis (see Döderlein, Japanische Seeigel, 

 I. Cidaridae u. Saleniidae. 1887. Taf. IX, Fig. 7 d), both in shape and in being 

 much more serrate along the edges of the blade (Pl. V, Fig. 15). The stalk is twice 

 as long as the head, without a limb. The tridentate and the small globiferous pedi- 

 cellariae do not differ from those of Ph. imperialis. 



Color dark violet, radioles uniformly gray. 



That this is a distinct species is evident enough. The great length of the 

 radioles makes it very conspicuous among the species hitherto known of this genus. 

 The slender ambulacral spines, the elevations on which the genital pores are situated, 

 as well as the characters of the large globiferous pedicellariae, and also the small 

 number of interambulacral plates, constitute a series of characters by which this 

 species is easily distinguished from all the other species of the genus Phyllacanihus 

 (viz. the species imperialis, parvispinus, magnijicus 1 and Thomasii). 2 The number of 

 coronal plates alone is sufficient to show that it has no nearer relation to the species 

 magnijicus and Thomasii ; from imperialis, which has also only 6 coronal interambula- 

 cral plates, it is very easily distinguished by the characters of the radioles and the 

 marginal ambulacral spines, as also by the elevation on the genital plates and the 

 shape of the large globiferous pedicellariae. Finally from Ph. parvispinus, which I 

 am inclined to regard as a distinct species, it differs, besides in the characters of 

 the radioles, ambulacral spines and genital plates, in a very marked way in the 

 characters of the large globiferous pedicellariae; these are in parvispinas very numer- 

 ous, on both the test and the peristome, and very short-stalked, the stalk being 

 only half the length of the head, and the valves are quite different in shape with 

 a much larger glandular cavity (Pl. V, Fig. 21). 



There are thus no less than three distinct species of the genus Phyllacanthv s 

 living alon^ the coasts of Australia. 



1 H. L Clark. The Echinoderms of the Western Australian Museum. Records W. A. Museum. I. 1914, 

 1». 158. Pl. XXVI. 



s A. Agassiz »k H. L. Clark, Hawaiian and other Pacific Echiui. The Cidaridae. Mem. Mus. Comp. 

 Zool. Vol. XXXIV. 1907. p. 15. Pls. 5, i— 17, 26, 5 — 8 and 27—30. 



