28 



GUIDE TO THE COKAL GALLERY. 



High Case 



III. 

 Table Case 



2 A, B. 



Fig. 



W^v 



Lower end' of a'.spi- 

 cule of the glass 

 rope magnified. 

 a, axial canals of 

 five aborted rays, 



Case III. 3) comes from Japan. Specimens of the 

 two species have been photographed together for 

 comparison. 



The fine specimen of Walteria leucJcarti, from 

 Sagami Bay, Japan (Fig. 9 ; and Case III. 3), 

 consists of a long hollow thick-walled tube rising 

 from a solid base, and with solid pinnate branches 

 arising from the tube at right angles ; the oval 

 sharp-edged openings in the wall of the tube are 

 oscules. The little elevations on the surface of 

 the l)ranches are caused by a commensal zoophyte. 

 Rhabdocalyptus victor (Fig. 10) and specimen in 

 Case III. 3, from the same locality as the previous 

 species, forms a deep thin-walled vase of felt-like 

 texture. 



The beautiful Lace Sponge, Semperella sclmltzei 

 (specimens in Case III. 1, and Table Case 2b), 

 has a straight or curved conico-cylindrical body 

 terminating below in a massive root-tuft. The 

 surface shows a delicate gauze-like network, the 

 dermal membrane (Fig. 11), and also long bands 

 and patches of coarsgr pattern ; the latter are sieve- 

 plates covering the oscules. In place of a simple 

 central cavity with one terminal oscule and sieve- 

 plate, as in Venus' Flower-Basket, there is a main 

 central cavity giving ofif lateral branching tubes, 

 the surface-openings of which are covered with the 

 sieve-plates ; accordingly currents enter the fine 

 gauze-like areas and leave by the coarser sieve- 

 plate areas. 



Hyalonema sieboldii, or the Glass-rope Sponge 

 (Figs. 8, 12) and specimen in Case III. 3, comes 

 from Japan, closely allied species, however, being 

 widely distributed. When the glass ropes (without 

 the upper portion of the sponge) first arrived in 

 Europe, they were supposed to be either artificial 

 productions or the axial core of Gorgonid Corals. 

 The twisted strand or glass rope is a root-tuft 

 composed of immensely long spicules, which root 

 the sponge in the mud, and which, at the upper 

 end, project like a spike into the interior of the 

 sponge-body. Some of the long spicules end in a 

 toothed disk, and are provided along their length 



