14 TH. MORTENSEN, ECHINOIDEA. 



Although I have no small specimens of damleyensis for comparison, I have 

 very little doubt that the present specimen really belongs to this species. At least 

 it is very closely related to this species, and from the material available no diffe- 

 rences can be pointed out. Tridentate pedicellariae are not found in this specimen. 



8. Heterocentrotus mamillatus (Klein). 



lleteruccntrotus mainillalns. A. Agassiz. 1872 — 73. Revision of tlie Echini, p. 133, 428, I'l. III. c, 



I'l. XXVI, Figs. 1-2, 14. ri. XXVIII, Fig. 8. 



» » I)e Loriol. 1883. Catalogue raisonnc des Echinod. rec. ... a Tile 



Maurice. Mem. Soc. de phys. et d'hist. nat. de Geneve, XXVIII, p. 35. 



» •-> Tii. MoRTENsEN. 1903. Ingolf-Ecliinoidea, I, p. 129. 



» -■ De Meijere. 1904. Siboga-Echinoidea, p. 102. 



» » II. L. Clark. 1912. Hawaiian a. o. Pacific Ecliini. The I'cdinidae . . . 



and Echinometridae, p. 378, PL 115—117. 



One dried specimen, labelled Cape Jaubert. 



9. Peronella Lesueuri (Val.) 



PI. V, Fig. 25. 



Laganmn Lesticnri. L. Agassiz. 1841. Monographic d'Echinod. vivans et fossiles. II. Des Scutelles, 



p. 116, Tab. 24. P'ig. 3-6. 

 Peronella decagonalis. A. Acassiz. 1873. Revision of the Ecliini, p. 521, PI, XIII. e. Figs. 8 — 10. 

 Laganmn Lesueuri. De Meijere. 1904. Siboga-Echinoidea, p. 122, Taf. VI, Fig. 63, 67, 70, Taf. 



XVIII, Fig. 329—333. 

 Peronella » H. L. Clark. 1914. Hawaiian a. other Pacific Echini. The Clypeastridae . . . Mem. 



Mus. C. Zool. Vol. XLVI, p. 53, PI. 124, Figs. 23—24. 

 Laganum » DOherlein. 1914. Echinoidea; Fauna Siidwest Australiens, p. 490. 



Peronella aphnoslina H. L. Clark. 1914. Echinoderins W. Austr. Museum, p. 167, PI. XXIV. 



Two large specimens, 130 mm long, labelled only West Australia 1911.. They 

 are of the typical shape, as figured in Tab. 24, fig. 3—4 in L. Agassiz' Monograph, 



Like H. L. Clark I do not find the component rods of the miliary spines 

 quite so abruptly widened as De Meijere figures them. Concerning the pedicellariae 

 I would remark that the larger tridentate form (PI. V, Fig. 25) appears to me some- 

 what more slender than figured by H. L. Clark, and there is a rather long slit 

 downwards from the outer widened part, while H. L. Clark figures the narrow 

 tubeformed part as closed up to where the widening begins. Ophicephalous pedicel- 

 lariae were not found. 



The Peronella aphnostiyia of H. L. Clark seems to me untenable as a separate 

 species. The differences in the shape of the test seem hardly sufficient for distin- 



^ The name Peronella i.s taken here in the sense of H. L. Clark, comprising the Laganids with 4 

 genital pores, those with 5 pores being referred to the genus Laganum. I would say, however, that 1 do not 

 feel convinced tliat this difference in the number of the genital pores corresponds to the natural relationship of 

 the Laganid species. But it is i)ractical and may be very conveniently used, until it has been jn'oved that 

 it is artificial and thus without generic value. 



