EXPLANATION uJ:- I'LA I t XVI. 



j!iiltiHiil lii(t:ii'clll. 



Fig. 5. IjiHigitiKliual section ot IkxIv Avall. 



,, 6. Terniiiiatiou of siplmii. 



,, 7. Anal vesicle and adjacent struct iiieh. 



,; S. Tliiee neplirustunies. 



Keterences to lettering: — 



"., anus; -/./•., aiial vesicle; //./'., body wall; '•.**/., circular niuscle ; 

 '/., deruiis; '/./'., dermal fibres; ep., epidermis; //.'■., gland cell; l.r.. 

 intestinal bloodvessel ; j.r., junction of intestinal and ventral vessels ; 

 I. III., longitudinal muscle; nn'x., mesentery; iit.s., mesentei'ic strands: 

 n.iii., oblique muscle; <«*•., ovary: /»A., pliarynx ; /•., rectum; v., seta; 

 ■•■•/'////., siphon ; tn'iili. t., Folded termination oF siphon; "., uterus; r.ii.r., 

 ventral nerve cord. 



