HOMOLAMPAS FRAGILIS. 57 
the test. The primary spines are small, slender, and straight. The miliary 
spines, similar in structure to the primaries, are not more than a third 
to a quarter their length. When covered with sjoines, the coloring is of a 
dark greenish violet ; denuded, the test is of a pinkish gi'ay. 
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 the anterior ambulacral plates towards the actinostome, as well as the 
posterior lateral ambulacral areas on each side of the actinal plastron, are 
left bare. The posterior lip of the actinostome is but slightly developed 
(PL XXIV. Figs. 9, 13) ; there is a tendency to the formation of rudimentary 
bourrelets from the crowding of small secondary tubercles on the interambu- 
laci-al edges of the actinostome (PL XXIV. Fig. 13). The anterior part of 
the actinal opening is covered by eight large polygonal plates of irregular 
outline ; the remaining space on the posterior part of the actinostome along 
the actinal lip (PL XXIV. Fig. 13) is covered by smaller irregulaily arranged 
plates. The actinal plates all carrj^ minute secondary tubercles. 
The anal system (PL XXIV. Fig. 14) 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 Palajotropus, short-stemmed, stout-headed, and 
short-stemmed, large-headed trifid pedicellariaj. Scattered irregularly over 
the test are long-stemmed, large, slender, open-headed trifid pedicellariae. 
Homolampas fragilis A. Ag. 
Homolampas fragilis A. Ac. Bull. M. C. Z., V., No. 9, p. 191, 1878. 
Florida Bank, Lesser Antilles. 734-1920 iathoms. 
Fragments of a large specimen of Homolampas, very probably the adult of 
H. fragilis A. Ag., of which young specimens were dredged by Mr. Pourtales 
(see Revision of the Echini, PL XVII. Figs. 13-21). These fragments show 
H. fragilis 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 (PL XXIV.). The Caribbean species differs from it, however, 
by the closer tuberculation of the miliaries, the larger number of primary 
