5. Merlarai'uaa roosevelti new species 
Holotyps .-— fhe sponge (U.S.S.M. no. ) was scraped fro® an old 
anchor chain at llizaheth Bay, Alhemarle Island, Gfalapagos, Jnly S6, 193^ 
(Sta. 20«3^)> 1^ cowers sone other ohject, perhaps a hamacle, and is one 
or two milliffleters thick. 
Description . — Oolor nearly white, consistency soft, fhe entire 
organism is veiy fine-grained, with pores and oscules too small to he mde 
oat. fhe most remarkable items involved concern the iriceleton; three sorts 
of spicales are present. 
1. Ectosomal special spicales are tylotes 3 ^7 raicra. 
2. Bndosomal spicules ftre ahandant acanthostyles, 
heads with tubercles rather than spines, size 11 by 
120 to 15 by 170 micra. 
3. Mlcroscleres are abundant arcuate isochelas with a 
semi circularly curved shaft and very small clads; 
the chord diameter varies from 21 to 24 raicra. 
lemarks . -—A review of the genus Merriamlum a nd a key to its several 
species is here presented to indicate better the relation of the new species 
to the members of the genus and also their relation to each other. 
List of previously known species of the Oenus Merri^iua 
a. MerrlamiufflB atleaiticuia was described as le tvodoryx a. by Stephens I916, 
p. 238, from Ireland, fhe ectosomal spicules are inequi ended strongyles. 
fhe mdoaomal spdcules vary from entirely spined to spined only on the heads. 
All the spicules are much larger than in roosevelti . 
4. Merriamium buchani was described as Ltasodendoryg by fopsent, 1913» 
p. 626, from the Antarctic, fhe ectosomal spicules are hastate tornotes. 
fhe endosomal spicules are only rarely tuberculate, and all the spicules 
are nnxch larger than In roosevelti . 
