EXPLANATION OF PLATES. 



T] • figures ilustrating this ^jr^r were dr. 

 to the sane scale of magnification, 330 diameters, 

 and were reduced one half in reproduction. 



Figures 1,2,4,6,7,0,17,31 and 32. were recon- 

 structed from series of transverse end sagittal 

 sections. 



In ell cases the part Df the figure which is 

 1 • et the top oi 1 the plate is either anterior or £&£. 

 ventral in the larva. 



ABBREVIATIONS USED. 



ael Left an*-? rocoele . 



aer Right anterior enterocoele. 



ap Apical plat ; . 



an sin Axial sinus. 



b Bl- stcpore . 



chi ,2,3 ,4. Ciliat :d bonds . 



eg Cireu] ves . 



cm Circu! ■ nesentery. 



op Cellul ;.r plug. 



I Dorsal pore . 



ee Epigastric enterocoele . 



