No. 2.] STRUCTURE OF TWO FISH TAPEWORMS. T^^J 



EXPLANATION OF PLATE XVL 



The figures are drawn at the scale indicated and, unless otherwise stated, with 

 the Abbe camera lucida. Sections from which drawings were made were stained 

 with haematoxylin. 



REFERENCE LETTERS. 



ca. calcareous bodies. 



ci. cirrus. 



cm. circular body muscles. 



c.p. cirrus pouch. 



ct'. external cuticular layer. 



ct. internal cuticular layer. 



cl.gl. gland cells. 



d.ex. excretory ducts. 



ep. epithelial layer. 



ep.cil. ciliated epithelium. 



l.m. longitudinal body muscles. 



m.c.ct. circular subcuticular muscles. 



m.l.ct. longitudinal subcuticular mus- 

 cles. 



ms. circular muscles. 



tnp. longitudinal muscles. 



«. nerve. 



n.r. nerve ring. 



Figs. 1-20. Proteocephalus ambloplitis. 



Fig. I. Lateral view of scolex. x 25. 



Fig. 2. Anterior view of scolex. x 25. 



Fig. 3. Median sagittal section of scolex. x 50. 



Fig. 4. Proglottids showing extruded cirrus, x 25. 



Fig. 5. Proximal portion of extruded cirrus, x 100. 



Fig. 6. Oocapt and beginning of oviduct. X 500. 



Fig. 7. Dorsal view of scolex, showing portion of nerve ring and the longi- 

 tudinal nerve trunks. 



Fig. 8. Transverse section showing nerve ring with branches to suckers. 



Fig. 9. Reconstruction of frontal sections showing the organs in a proglottis. 

 Camera outlines. X 50. 



Fig. to. The intra-ovarial region with enclosed female organs. X 100. 



Fig. II. Section through cuticula and subcuticular structure, x 2000. Not a 

 camera drawing. 



Fig. 12. Section through ootype, shell gland, and vitelline reservoir, x 250. 



Fig. 13. Termination of longitudinal excretory ducts in the posterior proglottis. 

 X 25. Not a camera drawing. 



Fig. 14. Transverse section of very young proglottis, showing the eight longi- 

 tudinal excretory ducts. X 25. Not a camera drawing. 



