Plate XVII. 



Fig. 1.— A photomicrograph of a BPntion cut from the surface of a Dneinone ix baU 

 (Sen I'lpnre 5, I'liite III.) HhowiiiK numfron.^ tiiljules out nt various angles. 



Fig. 2.— A photomicrograph of a snction from a reRiilar Daemonellx, sUowiug two tubules, 

 the upper one cut taugeutially, the lower one obliquely. 



