PERIVI5CERAL FLUID OF ECHIXODERMS. 



237 



made and the subsequent regeneration observed. But before 

 discussing the observations the relationships of the stereom and 

 the adjacent region should be described. Thus in a section 



pr. 



r> - 



st 





>rg.mbr. 



nc.sy. 







l-i R :i. Slron Jruhia. . vertical 



i. X 75- 



!'[.. j j. l>i-t.n! . : : ;ifuluiii . membrane of bod; .ill >lio\vn in 



Semi-diagrami 



!MK'. J.s. Detail . '. n in l-"m. 2.5. S-mi-liugrammatic. 



< 650. am idth -I'li'-iuliV; cp., i-pidermis; 



la.. l;u 11: : nn; pr.. \>T< .A area; pt.. peritoneum; 



rg.mb.. n-yi-ii- yncytium; trab., 



trabecula. 



through the bi'.h \\.iil "t .S. drobachiensis which had been decalci- 

 fied ami -laiiu-d the following relations of the stereom and the 

 surrounding ti tie- may be observed. The epidermis (Fig. 23) 

 appeal- nn the outer surface of the section and beneath this there 



