82 W. N. F. WOODLAND 



Fig. 6 (x cir. 7). — Diagrams representing the general arrangement of 

 the excretory channels in the anterior third of the worm and the two 

 main channels throughout. 



Fig. 7 ( X cir. 950). — Portion of a very fine excretory canal. 



Reference Letters in Figures 8-14. 

 BAY, terminal bay or inlet at hind end of body ; bm, boring muscle ; 

 CMO, median opening of the ductus eiaculatorius ; ct, connective tissue 

 investment of ducts ; dej, ductus ejaculatorius ; exb, junction of two 

 lateral main excretory channels ; re, fertilization chamber ; leg, lateral 

 main excretory channel ; mtd, muscular tissue round ductus ; O, ovary ; 

 OTP, ootype ; OVD, oviduct ; pap, pa])illa with terminal opening of ductus ; 

 PE, penis ; PRO, proboscis ; rh, receptaculum seminis ; RV, receptaculum 

 vitelli ; SD, sperm duct ; shgl, shell gland ; ted, terminal excretory 

 duct with opening to the left of ductus ; tes, testes ; u, uterus ; u 1, u 2, 

 U 3, first, second, and third limbs of the uterus ; uo, opening of uterus ; 

 VAG, vagina ; vd, vitellme duct ; vit, vitellaria ; vop, opening of vagina ; 

 ZD, zygote duct. 



Fig. 8 ( X cir. 7). — Dorsal aspect of the general reproductive apparatus 

 of Amphilina paragonopora, with three diagrammatic transverse 

 sections in the region of the ovary to show the relative dorsal and ventral 

 positions of the various ducts. 



Fig. 9. — Diagram of the general reproductive apparatus of Amphilina 

 foliacea, for comparison with fig. 8. 



Fig. 10 ( X cir. 660). — -The base of the ovary and associated ducts. 



Fig. 11 ( X cir, 660). — ^.Surface view of the posterior ending of the ductus 

 ejaculatorius, vagina, and lateral main excretory channels. 



Fig. 12 ( X cir. 63). — -Reconstruction from serial longitudinal sections 

 of the structures shown in fig. 11. 



Fig. 13 ( X cir. 3.30). — ^Testes oj^ening into the vas deferens. 



Fig. 14 ( X cir. 330). — Vitellaria openmg into the vitelline duct. 



Plate 4. 

 Reference Letters in Figures 15-25. 



ancc, giant anchor- cells ; bm, boring muscle ; CALC, calcareous bodies ; 

 LEC, lateral main^excretory channel ; o, ovary ; pro, proboscis ; rtm, 

 retractor muscle of proboscis ; ser, serrated cuticle of proboscis ; tes, 

 testes ; tt, terminal thickenmg of proboscis ; u 1, u 2, u 3, first, second, 

 and third limbs of uterus ; uo, opening of uterus ; ^^T, vitellaria. 



Fig. 15. — Sketch of proboscis everted (a) and retracted (b), dra-R-n from 

 the living animal. 



Fig. 16 { X cir. 78). — Everted proboscis in longitudinal section. 



Fig. 16, a ( X 1060). — Serrated cuticle covering proboscis. 



Fig. 17 ( X cir. 78). — Introverted proboscis in longitudinal section 

 (drawn from a whole-mount specimen). 



