PLATE XXI. 



Figs. 1-6. Polycarpa tinctor, Quoy and Gaimard. 

 Figs. 7-14. Polycarpa viridis, Herdman. 



Fig. 1. Polycarpa tinctor, a specimen from the left side ; natural size. 



Fig. 2. Another specimen from the right side ; natural size. 



Fig. 3. The anterior end of another specimen : natural size. 



Fig. 4. Part of the branchial sac of Polycarpa tinctor, showing a fold (br.f.), seen from 



the inside; magnified (Hartn., obj. 4). 

 Fig. 5. A small portion of the last figure ; more enlarged (Hartn., obj. 5). 

 Fig. 6. The dorsal end of the anterior extremity of the branchial sac, showing the dorsal 



tubercle (d.t.), and part of the circle of tentacles (tn.) ; slightly enlarged. 

 Fig. 7. Polycarpa viridis, a specimen from the right side ; natural size. 

 Fig. 8. Another specimen, seen from the right side ; natural size. 

 Fig. 9. A small part of the test of Polycarpa viridis, showing the network of vessels (v.) ; 



magnified (Hartn., obj. 4). 

 Fig. 10. Part of the branchial sac of Polycarpa viridis, showing a fold (br.f.), seen from 



the inside ; magnified (Hartn., obj. 4). 

 Fig. 11. A small part of the last figure, more highly magnified, showing the arrangement 



of the muscular bundles (Hartn., obj. 5). 

 Fig. 12. The dorsal tubercle (d.t.), the peritubercular area, and part of the circle of 



tentacles (tn. and tn.'), of Polycarpa viridis; magnified (Hartn., obj. 4.) 

 Fig. 13. One of the " polycarps," showing the ovary and the oviduct (o.d.), and vas 



deferens (v.d.) ; magnified (Hartn. obj. 4). 

 Fig. 14. A small portion of the testicular part of the polycarp, showing the testicular 



vesicles (t.v.), and the vas deferens (v.d.) ; highly magnified (Hartn., obj. 5). 



