'jOO 



PLATE LXXX. 



Hymedesmia simplicima, Boioerhank. 



Fig. 1. — Represents a portion of the type-specimen 

 of the species X 123 linear, exhibiting the mode of 

 disposition of the skeleton fasciculi. 



Hymbeapiiia simplex, Boioerhanh. 



Fig. 2. — A portion of the type-specimen of the spe- 

 cies X 123 linear, showing the skeleton and external 

 defensive spicula and the attenuato-spinulate, internal, 

 defensive spicula in situ. 



Fig. 3. — Two of the internal, defensive spicula 

 X 250 linear, exhibiting the variety of their forms and 

 the degree of their spina tiou. 



Hymedesmia simplicima, Bowerbank. 

 Plate LXXX. 



Sponge. Coating. Surface uneven, but smooth, 

 Oscula simple, dispersed. Pores inconspicuous. 

 Dermal membrane pellucid, aspiculous. Skeleton fas- 

 ciculi mostly niultispiculous, occasionally formed of 

 very few spicula. Spicula spinulate, very rarely 

 acuate, large, and long, intermixed with very long, 

 slender, and often sinuous ones of the same form. 



Colour. — In the dried state cream white. 



Habitat. — Shetland, off Balta; Rev. A. M. Norman. 



Examined. — In the dried state. 



I received a single specimen of this sponge for ex- 

 amination from the Rev. A. M, Norman, who dredged 



