22 Art. I. — X. Annindale and T. Kawamura : 



The gemmules are either fastened together in groups that lie 

 free in the suhstance of the sponge or else adhere in a single layer 

 at the base. Each has a curved foraminal tubule that projects 

 outwards or upwards through the pneumatic coat. 



The following are the Japanese localities of the species: 



Lake Noziri, Lake Aoki, Lake Nakatsuna, Lake Kizaki and 

 Lake Suwa, Province of Shinano. 



Tokyo. 



Lake Biwa. 



Lake Ogura near Kyoto. 



Genus Ephydatia Lamouroux. 



This genus is distinguished from all others by the following 

 characters: — 



1. There are as a rule no true flesh-spicules (free micro- 

 scleres), but immature gemmule-spicules often lie loose in the 

 parenchyma Microscleres with more than one main axis are 

 always absent. 



2. The gemmule-spicules consist of a cylindrical shaft that 

 bears a well-defined disk or rotule at each extremity. The two 

 disks of each extremity are equal or at any rate similar; their 

 margins are indented, denticulated or serrated. 



Only one Japanese species, with two varieties, can be assigned 

 to this genus, namely Ephydatia mulleri (Liebk.), an almost cos- 

 mopolitan sponge. 



Ephytfafia mü fieri (LlEBK.). 

 1909, Weltner, Brauers Süsswasserf .luua Deutschlands XIX, p. 186, figs. 318-320. 



The sponge forms more or less flat growths that are often 

 thickened and irregularly nodular in the central region. 



It is never very massive and never produces slender branches. 

 The skeleton is compact but fragile. Vesicular cells ("bubble- 

 cells ") are always abundant in the parenchyma. 



In the typical form the skeleton-spicules, which are always 



