224 PLATE LXXVl. 



Fig. 11. — Au average-sized spiculum fi'om tlie 

 primary lines of tlie skeleton. X 250 linear. 



Fig. 12. — One of tte inequi-cylindrical, incipiently 

 spinous spicula from the secondary lines of tlae skele- 

 ton. X 250 linear. 



Raphiodesma soedida, Bowerhanli. 



Fig. 13. — Represents tlie type-specimen from Jersey 

 in tlie cabinet of the Rev. A. M. Norman. Natural 

 size. 



Fig. 1-1. — One of the subclavate, fusiformi-acuate, 

 tension spicula from the dermal membrane. X 250 

 linear. 



Fig. 15. — A long and slender, tricurvate, acerate 

 tension spiculum from the dermal membrane. X 250 

 linear. 



Fig. 16. — One of the contort, bihamate, retentive 

 spicula from the dermal membrane. X 630 linear. 



Fig. 17. — One of the small, dispersed, bidentate, 

 inequi-anchorate retentive spicula. X 530 linear. 



Fig. 18. — A large, dentato-palmate, inequi-anchorate, 

 retentive spiculum from one of the rosette-shajjed 

 groups of spicula. X 530 linear. 



Fig. 19. — One of the skeleton spicula. X 250 

 linear. 



IsoDiCTYA OBSCURA, Bowevhanlc. 



Plate LXXVI. 



Sponge massive, sessile ; surface even, but slightly 

 rugose or papillate. Oscula simple, dispersed. Pores 

 inconspicuous ; dermal membrane pellucid, aspiculous. 

 Skeleton rather compactly constructed, internally 

 regular ; primary lines rarely consisting of more than 

 three or four spicula ; secondary lines unispiculate ; 

 short and stout. 



