148 LILIAN SHELDON. 



Fig. 3. — Longitudinal section through the ciliated pit and nervous system 

 of a larval Amaraecium immediately before hatching. The ciliated pit com- 

 municates with the two portions of the nervous system. (Oc. 2, obj. D.) 



Fig. 4. — Alimentary canal of Cynthia rustica, seen from the left side. 

 Drawn from a dissection. 



Fig. 5. — Transverse section through the dorsal lamina of C. rustica and 

 three branchial bars and slits. (Oc. 2, obj. C C.) 



Fig. 6. — Transverse section through one of the stomach glands of C. 

 rustica, showing the two kinds of cells by which it is lined. 



Fig. 7. — A portion of the wall of the pharynx of C. rustica, showing 

 the arrangement of the branchial slits and skeletal system. Drawn from a 

 picrocarmine-glycerine preparation. (Oc. 2, obj. B.) 



Fig. 8. — Transverse section through the anterior end of the endostyle of 

 C. rustica, where its edges have fused to form a tube. (Oc. 4, obj. B.) 



Fig. 9. — Transverse section through the endostyle of C. rustica in its 

 middle region. (Oc. 4, obj. B.) 



Fig. 10. — Transverse section through one of the cirri in the buccal cavity 

 of C. rustica, showing its four lobes, two of which are provided with 

 cilia. (Oc. 2, obj. D.) 



Fig. 11. — Transverse section through a small portion of the wall of the 

 intestine of C. rustica, showing the adjacent liver-cells with their fibrous 

 walls and granular contents with concretions. (Oc. 2, obj. E.) 



Fig. 12. — Diagrammatic transverse section through a C. rustica, near 

 its base, showing the various organs and their relations to one another. 



Fig. 13. — Section through a testis of C. rustica, showing it filled with 

 spermatozoa and surrounded by a delicate membrane, outside which are 

 muscles and pigment-cells. At one end it is seen to be continued into a duct. 

 (Oc. 2, obj. C C.) 



Fig. 14. — Transverse section through the generative organs of C. rustica, 

 showing the testes, with their ducts, and the ova lying respectively on the 

 outer and inner side of the generative duct. (Oc. 2, obj. A, reduced half.) 



Fig. 15. — Transverse section through a small portion of the body wall and 

 pseudoccele, showing the muscle layers and connective -tissue meshwork, with 

 the different kinds of cells in it. A process from the pseudoccele projecting 

 into the atrial cavity is cut through. (Oc. 4, obj.C C.) 



