HOMOLAMPAS ' RAGILIS. 



the test. The primary spines are small. Blender, and straight. The miliary 

 spines, similar in structure to the primaries, are nol more than a third 

 to a quarter their length. When covered with spines, the coloring is of a 

 dark greenish violel ; denuded, the test is of a pinkish -ray. 



On the actinal side (PI. XXIV. Fig. 9) the primary tubercles are more 

 closely packed in the interambulacral areas and on the actinal plastron, 

 but tin- anterior ambulacral plates towards the actinostome, as well as the 

 posterior lateral ambulacral areas on each side of the actinal plastron, are 

 [efl hare. The posterior lip of the actinostome is bul slightly developed 

 | PI. XXIV. Figs. 9, L3) ; there is a tendencj to the formation of rudimentary 

 bourrelets from the crowding of small secondary tubercles on the interambu- 

 lacral edges of the actinostome i PI. XXIV. Fig. 13). The anterior part of 

 the actinal opening is covered by eighl large polygonal plates of irregular 

 outline; the remaining space on the posterior pari of the actinostome along 

 the actinal lip I PL XXIV. Fig. L3) is covered by smaller irregularly arranged 

 plates. The actinal plates all carry minute secondary tubercles. 



The anal system (PI. XXIV. Fig. L4) is circular, surrounded by two or 

 three concentric rows of irregularly arranged plates. 



The large actinal tentacles are fimbriated; towards the ambitus and be- 

 yond it, until they reach the extremity of the petals, they become simple 

 with a slight sucker. The tentacles of the petaloid region are broad,flat- 

 tened, with an indistinct sucking disk. 



The ambulacra carry, as in Palaeotropus, short-stemmed, stout-headed, and 

 short-stemmed, large-headed trifid pedicellari®. Scattered irregularly over 

 the test are long-stemmed, large, slender, open-headed trifid pedicellariae. 



Homolampas fragilis a. a.;. 



Homolampas fragilis A A,;. Hull. M. ( !. Z., V.. No. 9, p. 191, 1878. 

 i Bank, b w t Antilles. 734 1920 fathoms. 



Fragments of a large specimen of Homolampas, very probably the adult of 

 //. fragilis A. Ag., of which young specimens were dredged by Mr. Pourtales 

 (see Revision of the Echini, I'l. XVII. Figs 13-21). These fragments show 

 Kfraffitia to be closely allied to the large species of the same genus {H. 

 fulva, A. Ag.) described and figured in the Report on the Echinoidea of the 

 Challenger (PI. XXIV.). The Caribbean Bpeciea differs from it. however. 

 by the closer tuberculatum of the miliaries, the larger number of primary 



