282 HAWAIIAN AND OTHER PACIFIC ECHINI. 



tuherculatus becomes the type-species of Heliocidaris. This leads to some 

 interesting but not very important nomenclatural changes which will be found 

 fully discussed under Heliocidaris (p. 350). 



The genus Evechinus is characteristic of the New Zealand region and so far 

 as known there are no authentic records from elsewhere. There are specimens 

 in the M. C. Z. collection labelled "Fiji," but they are old and bare. They were 

 the gift of a sea-captain, and if obtained in Fiji, they were probably taken 

 there from New Zealand. The genus is as isolated structurally as it is geo- 

 graphically but, as already suggested, it is probably a highly specialized Echinus 

 and may find its nearest hving relative in E. armatus (de Meij.). The genus 

 appears to be monotypic. In spite of Farquhar's very strong evidence to 

 the contrary, Mortensen thinks Bell's species rarituberculatus may be valid, 

 because the tridentate pedicellarise are slightly different from those of chloroticus. 

 As I have found the form figured by Mortensen for rarituberculatus, mingled 

 with the ordinary form of chloroticus on the same specimen, there is no doubt 

 that Farquhar's view is correct; ?'. e. that rarituberculatus is the young of 

 chloroticus. As for Wood's Evechinus australice, a careful reading of his descrip- 

 tion, with specimens of Tripneustes in hand, shows that the bare tests upon 

 which his species is based, are simply young Tripneustes. The arrangement of 

 the pores, the shape of the auricles, and especially the fact that the ambulacra 

 are broader than the interambulacra constitute evidence scarcely to be doubted. 



TOXOPNEUSTES. 



L. Aga.ssiz, 1841. Int. Mon. Scut., p. 7. 

 Typc-spccies, Echinus pilcolus Lamarck, 181G. Anim. s. Vert., Ill, p. 45. 



In spite of the fact, referred to on p. 245, that Toxopneustes elegans Dod. 

 forms a connecting link with Lytechinus, this is a very natural and easily recog- 

 nized group. The broad poriferous areas, the short primaries, the abundant 

 tubercles, and the deep gill-slits combined with the absence, on many ambulacra! 

 plates, of primary tubercles adjoining the poriferous area, give the members of the 

 geims an easily recognized appearance. Indeed the characters of the test are so 

 uniform, that tlie most obvious and perhaps the best specific characters are found 

 in the coloration. The difference in tuberculation between roseiis and pikoliis, 

 to which Mortensen refers ("Ingolf" Ech., p\. 1. p. 112) is not constant, and 

 some specimens of pilcolus from Japan cannot be distinguished in this respect 

 from rosciis. Since color seems to be the best criterion in this genus for detcrmin- 



