478 
PROTOZOA . 
Platyohalinay g. n., Elilers (^Chalinece), Leaf-shaped, with some acute 
conical prominences and scattered circular oscula, a regular mesh of homy 
fibres, enclosing single thin spicula, pointed at both extremities. Type 
P. foliacea, Cape of Good Hope. 
JRhap\K]idophlus, g. n., Ehlers (Fibrinece^. Sponge reticular, with a dense 
corticate layer of spicula, pointed at one end, obtuse at the other j below it 
a net of horny fibres, enclosing and surrounded by spicula of the same 
description, further spinous spicula, symmetrical double anchors and sili- 
ceous fibres, bent in various manners. Type R. craticia^ Esp., India. 
Trikentrion [2'ricentriuin\ g. n., Ehlers {Fihrinece). Branched, surface 
rough ; internal tissue thickened into horny fibres and rows of spindle-shaped 
spicula; in the superficial tissue trifid spicula, one branch spinous. F.muri- 
(uitwn, Esp., Guinea. 
IXomoiodictya, g. n., Ehlers {Compayinece). No definite shape ; tissue with 
regular net-shaped rows of single spicula, with symmetrical double anchors. 
Type H. digitata, Esp. (palmata, Johnst.), Norway. 
Myrmekioderma \^Myrmec-~\, g. n., Ehlers (Compaginece). Of no definite 
shape, with a warty crust of crowded spicula pointed at both ends, 
interrupted by membranous spots with larger and smaller oscula leading 
into the channel-S3"steni of the sponge ; internal tissue without horny fibres, 
but with irregularly aiTanged smooth or spinous spicula pointed at both 
e.xtremities. Type M. gramlatum, Esp., India. Ehlers, /. c. (Q). 
Trichodemma, g. u., Sars \ Corticatd) (18, p. 62, pi. vi. figs. 1-15). Spongia 
silicea, simplex, libera, in limo demersa et hie fimbria spiculorum setifor- 
mium, flexibiliuni, radiantium sustentata, cortice crasso compacto circum- 
data, interiore multo minus compacto, parenchymatoso, lacunis numerosis 
irregularibus trajecto. Oscula numerosa tubiformia in facie superiore libere 
prominentia. Sceletum ex spiculis acuformibus fasciculato-radiantibus com- 
positum, aliis brevissimis capite globoso in cortice densissime accumulatis, 
nliis multo longipribus, fasciculos tenues parenchyma et corticem trajicientes 
formantibus. 1\ hemisphcsricum, sp. n., id. 1. c., Lofoden Isles, 120-300 fath. 
Cutdorhiza, g. n., id. I c. p. 66, pi. vi. figs. 16-84. (A remarkable shrub-like 
siliceous sponge, which might be taken for a Sertularian or Polyzoan.) 
Spongia silicea ramosa, fasciculis densis spiciflorum acuformium axeni 
solidam formantibus sustentata, radiculis numerosis arborescentibus ex 
spiculis ejusdem generis formatis in limo affixa. Parenchyma axem internam 
corticis instar circumdans, spiculis superficialibus anchoratis et bihamatis 
ornatum. Oscula et pori nulla. Ova iu apicibus dilatatis ramorum se 
evolventia. C. abysswoIUf sp. n., id. 1. c., Lofoden Isles, 300 fath. 
Ilyalonema longissmmm, sp. n., id^l. c. p. 70, pi. vi. figs. 35-45, Lofoden, the 
Atlantic, and Greenland Seas. Nearly allied to II. boreale, Lov«5n [therefore no 
true Hyalonema]. The occurrence is announced of a sponge of similar shape 
in 150-309 fath. in Hardangerfjord, but of an entirely different generic type, 
according to the spicula. 
, Graydla cyaihopkoray Cart. (Zool. Rec. vi. p. 660), is noticed as occurring 
in the Gulf of Suez, with the following generic diagnosis : — Sponge mas- 
sive, expanded or subgiobular, attached by an expanded base ; outer surface 
covered with a smooth, fleshy skin, with numerous, regular, equal-sized, 
flat-topped, low tubercles. Sponge flesh}'^, with siliceous fusiform elongate 
spicula of one form.” Ann. N. II. (4) x. p. 124. 
