PROF. OWEN ON A NEW SPECIES OF EUPLECTEI-LA. 123 



DESCRIPTION OF THE PLATE. 

 Tab. XXI. 



Fig. 1. Euplectella Cucumer, nat. size ; with the foreign sponge and other bodies to which it is attached : — 

 A. wall of the cylindroid, or parietal portion ; B. terminal grating or lid ; a. parietal orifices ; 

 c. confluence of longitudinal fibres ; d. ibid, prior to forming the network of the lid ; e. ibid, as 

 the cylindroid conti-acts towards its attached end ; h. resolved filaments, reflected from the 

 attached body ; o, o'. oblique fibres ; p. prominent lines from the oblique fibres, chiefly due to 

 the multiradiate accessory spicula ; r. rim or thickened transverse line at the attached border 

 of the lid ; t. transverse fibres. 



Fig. 2. The opposite side of the attached end of the Euplectella Cucumer, with the substance to which it 

 adheres : — h. the free ends of the resolved filaments : nat. size. 



Fig. 3. The reticulate grating or soldered Ud of the Euplectella Cucumer : nat. size. 



Fig. 4. A closed and an open interspace of the meshwork, magnified four diameters : — a. the open 

 space ; b. longitudinal fibres ; t. transverse fibres ; k. superficial objique fibres closing an inter- 

 space ; 0. deep-seated fibres ; o'. intermediate fibres. 



Fig. 5. A multiradiate spiculum, from the place of intersection of the superficial oblique fibres, magnified 

 eight diameters. 



Fig. 6. Portion of a barbed filament with its terminal anchor, magnified twenty diameters. 



Fig. 7- Transition of the barbed to the smooth structure in one of the filaments, similarly magnified. 



Fig. 8. A portion of a sponge from the mass to which the Euplectella adheres ; natural size, and mag- 

 nified ten diameters. 



Fig. 9. Another portion of sponge from the same mass ; natural size, and magnified ten diameters : — 

 2a. one of the squares of the harrow-like structure, magnified twenty diameters. 



n.'l 



