446 
Proceedings of Royal Society of Edinburgh. [sess. 
EXPLANATION OF PLATE. 
B. = Bursa. 
Cut. = Cuticle. 
C.M. = Circular Musculature. 
ECT. = Ectoderm. 
END. = Endoderm. 
G.AP. = General Aperture. 
P. = Penis. 
SC. = Sub-cuticle. 
Fig. 1. Female of Echinorh ynchus a?itarcticus, n. sp. x 10. 
Fig. 2. Types of rostral hooks in series. 
Fig. 3. (a) Tail of female, showing cleft. x 12. 
( b ) Tail of male, with penis and bursa extruded. x 12. 
Fig. 4. Surface view of body-wall as seen from inside, to show 
ramification of sub-cuticular canals. x 12. 
Fig. 5. Section of body-wall through spiny region. x 220. 
Fig. 6. Detractor muscles of rostral sheath. x 220. 
Fig. 7. Rostrum and portion of disc. x 30. 
Fig. 8. Triple-shelled embryo. x 220. 
{Issued separately January 4 , 1907 .) 
