BY R. VON LEXDENFELD, PH.D. 531 



EUSPONGIA OFFICINALIS CAVERNOSA, 



is bulbous, turnip-shaped (described by Ridley (I.e.), from a single 

 dry specimen), with several tubular processes on its upper surface, 

 10-35 mm long, and 8-10 mm. in their greatest diameter. These 

 processes however are ragged in outline at their distal ends and 

 evidently in life opened through their fringed apertui'e, now 

 obscured fiom the falling together of the sides. Their sides are in 

 some cases fenestrate. The body of the sponge is rudely globular, 

 and is drawn up above into monticular elevations, which are 

 terminated by the tubes just described ; the base is somewhat 

 flattened and has been attached at more points than one. The 

 horizontal diameters are 45 and 55 mm. The vertical height to 

 base of uppermost tube is 30 mm. 



From this description which is copied verbatim from Ridley 

 (I.e.), it appears that this variety is most similar to my species 

 Euspongia conifera. I will leave it however to Mr. Ridley to 

 decide this, whether they ai'e identical or not. 



Euspongia officinalis dura, 

 Spongia lignea levis. Hyatt (I.e.) 



I have but one dry specimen and also Hyatt's description, which 

 is not accompanied by an illustration, is very meagre. The shape 

 of this variety is irregularly massive, horizontally expanded, with 

 indications of irregular conic elevations on the sides and upper 

 surface. My specimen measures 140 x 160 x 80 mm. 



Rigidity. 



Some of the varieties of this species are exceedingly soft and 

 elastic, to this peculiarity of them theii- utility must be ascribed. 



The variety Euspongia officinalis dura, is as the name implies 

 very hard. By the pressure of 1 kilogramme the specimen of 

 which the dimensions have been given above is compressed only 



