72 GEODIA JAPONICA. 



Geodia japonica (Sollas). CeJ^T 4 



Plate 37, figs. 15-30; Plate 38, figs. 1-29; Plate 39, figs. 1-41. 



Thiele, Zoologica, 1898, 24, p. 7, taf. 2, fig. 1; taf. G, fig. 3. Lendenfeld, Tierreich, 1903, 19, p. 111. 

 Cydoniuni juponinim Sollas, Rept. voy. "Challenger," 1888, 25, p. 256. 



There is in the collection a fine, dry sponge from Japan, which appears 

 to be identical with the species described by Sollas as Cydoniuni japonicum and 

 by Thiele as Geodia japonica. A part of the type of the former in the British 

 Museum I have, through the kindness of Mr. Kirkpatrick, been able to 

 reexamine. 



The sponge (Plate 38, fig. 8) has the shape of a low and broad, thick-walled 

 cup. It is 19 cm. high; its maximum and minimum transverse diameters are 

 24 and 22 cm. Near its margin the wall of the cup is about 3 cm. thick; the 

 margin itself is bent inward; it is interrupted in two places by broad indentures. 

 The cavity of the cup is cm. deep. The base of the sponge measures 11 Xl3 

 cm. and exhibits a cup-shaped depression like the upper one, but much smaller, 

 only 4^ cm. deep. The inner surfaces of both the upper and the lower cup are 

 rather irregular and undulating but destitute of higher protuberances. The 

 outer surface of the sponge is covered by large and conspicuous, terminally 

 rounded, lobose protuberances, IJ-B cm. broad and about as long, which hang 

 down stalactite-fashion. Most of them are attached with a considerable portion 

 of one side to the body of the sponge. In external appearance and in size it 

 corresponds with the specimens examined by Sollas and Thiele. 



In some of the narrowest, most sheltered fissures between adjacent stalactite 

 lobes a rather dense spicule-fur about 1.5 mm. high is observed. Apart from 

 this the surface is now entirely destitute of a spicule-fur. The whole of the 

 surface, also that of the margin of the cup, is dotted with small holes, the en- 

 trances to the radial cortical canals. Some of these holes are partly covered 

 by remnants of pore-sieves. In the specimen examined by Sollas there were no 

 holes (canal-entrances) on the margin of the cup. On the outer, lobose surface 

 the width of and the distances between these holes are quite constant, their 

 diameter here being about 300 p. and the distances between their centres about 

 700 /i. On the margin of the upper cup the holes are much smaller and farther 

 apart. In this upper cup the holes are more variable in size and much less 

 regularly distributed than on the outer surface, some being as much as 500 fx 

 wide. In extensive tracts of the lower cup, these holes are 400-450 /x wide and 

 the distances between the margins of adjacent ones smaller than their diameter. 



The colour (in the dry state) is white. 



