90 
Fig. 162. — Transverse section of posterior portion of 5. prolifer um: cal., calcareous corpuscles; ex. 
excretory canals: mus., muscles; r. n., reserve nutritive material, x 100. (After Ijirna, 1905, fig. 17.) 
Fig. 163.— Head end of S. proliferurn fully stretched; excretory vessel in part strongly swollen, x 30. 
(After Ijima, 1905, fig. 18.) 
