82 



Fig. 33. 3 of the contort-bihamate spicula from the extremity of a branch (magnified to the 

 same degree as the simple bihamate). 



34. A fully developed gemmule taken out of the parenchym of the sponge. 



Fig. 3545. Hyalonema longissimum. 



Fig. 35. 1 specimen with an unusually short stem, and much enlarged rectangularly bent 



root, very slightly magnified. 

 36. 1 other specimen with a longer stem and less enlarged root. 



37. The head or body with the upper part of the stem of a young specimen; shewing 



the fistular osculum, the exterior down of spicula, and the fine pores in the skin. 



38. The head of an other specimen split along the middle; shewing the fan-like expan- 



sion of the spicula of the stem in the interior, the great interior cavity opening 

 into the fistular osculum, and the parenchym with its lacunes and interstices. 



39. A thin lamella cut from the head perpendicularly to the surface ; shewing the radi- 



ating fascicles of spicula, the dermal layer and the exterior spicula. 



40. A piece of the stem; the lower part with its exterior skin; the upper part shewing 



the arrangement of the spicula in the axis. 

 41. A root-fibre, strongly magnified and partly freed from the adherent extraneous particles. 



42. Spicula: a, of the stem; 6, c, d, of the secundary radiating fascicles in the interior 



of the head; e, one of the spicula projecting beyond the skin; f, some of the small 

 spindle-shaped spicula irregularly imbedded in the dermal stratum (all equally 

 magnified). 



43. The middle of 2 of the fusiform spicula from the parenchym of the head, strongly 



magnified; shewing the very slightly marked medial enlargement, the axial canal 

 and the 2 different layers in the substance of the spicula. 



44. The end of .one of these spicula. 



45. One of the exterior projecting spicula, strongly magnified. 



