200 
ZOOLOGY OF THE FAR EAST. 
List of the Japanese species :— 
Spongilla {Euspongilla) lacustris, auct. Sfongilla {Eunapius) fragilis, Leidy. 
Spongilla [Euspongilla) semispongilla Ephydatia miUlen (Liebk.). 
(Annandale) . Ephydatia miilleri var. japonica (Hilgeii- 
Spongilla (Euspongilla) inarmata, sp. dorf). 
nov. Heteromeyenia kawamurae, Annandale. 
Spongilla ^ [Stratospongilla) dementis, 
Annandale. 
Spongilla inarmata, sp. nov. 
(Plate IX, fig. 2.) 
1917. Spongilla aspinusa, Annandale and Kawamura [nec Potts), Journ. Coll. Sci. Tokyo, 
XXXIX, p. 8, pi. ii, fig. I. 
I have compared a fragment of the sponge. from Lake Biwa noticed by Dr. Kawa- 
mura and myself under the name Spongilla aspinosa with an authentic specimen of 
that species from the United States of America and find the differences much greater 
than we believed to be the case. It becomes necessary, therefore, to describe the 
Japanese form as a new species. 
The sponge forms a thin, very brittle crust and has (dry) a yellowish colour ; the 
external surface is irregular and pitted, and upright bunches of spicules project 
through the external membrane in the form of spines. 
The skeleton forms a close, irregular network in which it is possible to distinguish 
only ill-defined and relatively broad spicule-fibres. 
The gemmules lie at the base of the sponge, probably attached to a basal mem- 
brane, of which only traces remain in the specimen examined. They are fairly numer- 
ous and vary considerably in size ; their outline is often oval. Each gemmule is 
covered with a rather thick layer of "granular" pneumatic substance and is enclosed 
in a regular network of macroscleres, which are sometimes slightly smaller than 
those of the skeleton. There is a single foraminal tubule, which is not conspicuously 
curved. 
The macroscleres are of moderate size, relatively slender, straight or feebly 
curved, perfectly smooth and sharply pointed at both ends. There are no gemmule- 
spicules. The flesh-spicules are practically confined to the dermal membrane ; they 
are slender, sharply and gradually pointed at both ends and as a rule somewhat cres- 
centic in form ; they bear short scattered spines on the middle region, but are smooth 
or almost smooth at the extremities. 
Measurements of spicules:— 
Length of macrosclere . . . . . . 0-288 mm. 
Breadth of macrosclere . . . . . . o-oi2 ,, 
Length of microsclere . . . . . . -052 — ••068 mm. 
Type-specimen. No. P, 49-1, Zool. Survey of India {Ind. Mus.). 
Locality. Lake Biwa, Japan (T. Kawamura: 24-7-15). 
