290 PnOF. ALOfAX ox THE T?ECK>'T EESEARCHES 



Thev have verified GreeflTs description of the skeleton as com- 

 posed of layers of hyaline siliceous globules ; but, like -Archer, they 

 tail to discover perforations in it, and find that the globules are 

 out loosely connected with one another and are easily detached 

 during the passage between them of nutritive matter. There is 

 a single nucleus, and also contractile vacuoles. The pseudopodia 

 which pass out between the siliceous globules are destitute of gra- 

 nules, and rarely show any tendency to branch. 



Another beautiful genus of skeletophorous Heliozoa is Itaphi- 

 diophrys. Archer. In the species referable to this genus the sphe- 

 rical body-mass is probably in every case differentiated into en- 

 Fig. 1.3. 



Baphiduyphrys elegans. A. colony of eight indi'iiduals united to one another by 

 bridges of protoplasm, the whole surrounded by a soft granular inrestment, in 

 which are immersed minute curyed spieula, and through which tl-e pseudopodia 

 are seen passing from the inner spheres to the surrounding water, a, nuclexis, 

 with its nucleolus yisible in one of the component spheres. (After Hertwig and 

 Lesser.) 



dosarc and ectosarc, and contains in the endosarc a single nucleus, 

 while from the peripheiy radiate in all directions very long un- 

 branched granular pseudopodia. 



External to the proper protoplasm -sphere is a soft granular 



