BY R. VOK LENDENFELD, PH.D. 551 



EXPLANATION OF PLATES. 



Note. — In all cases where no mention is made in the explanation of the 

 method in which the plates were drawn, Zeiss's new reflecting camera has 

 been employed, so that the relative dimensions are very reliable. 



Plate 36. 



Fig. L — Eic^jwngia canaliadata. E. v. L. Var. dura. 

 Skeleton. 

 Distal pai't of a transverse section through the massive part of the 



sponge. 

 50:1 magniiied. 



Fig. 2. — Eusj^onqia levis. R. v. L. 



Skeleton. 



Transverse section through the outer surface. 



50:1 magnified. 



Showing sand-grains in the skin (a), and large solitary sand- 

 grains in the network of the clear horny threads (b), (c) are 

 the spaces for the sub-dermal cavities. 



Fig. 3. — Euspongia irr-egidaris. R. v. L. Var. Jacksonia. 

 Skeleton . 



Portion of the network formed by the connecting fibres. 

 50:1 magnified. 



Fig. 4 — Euspongia reticulata, R. v.L. 

 Skeleton. 



Portion of the network formed by the connecting fibres. 

 50:1 magnified. 



Fig. 5. — Euspongia repeals. R. v. L. 

 Skeleton. 



Portion of the network 



Transverse section through the outer surface. 

 50:1 magnified. 



Fig. 6. — Euspo7igia Matthewsi. E. v. L. 

 Skeleton. 



Portion of the network, 

 50:1 magnified. 

 36 



