ii6 Transactions of the Royal Canadian Institute, [vol. x. 



Explanation of Figures. 

 All of the figures are camera-Iucicla drawings, excepting Figs. 34 to 

 41, inclusive, which are photomicrographs of sections or portions of 

 sections. 



c, cirrus. olm, outer longitudinal muscles. 



ccm, circular cuticular muscles. pc, cells of parenchyma. 



cm, coronal muscles. rmp, retractor muscles of cirrus. 



cmc, circular muscles of cirrus. rs, receptaculum seminis. 



en, collateral nerves. rvd, right vitelhne duct. 



cu, cuticula. sc, cells of subcuticula. 



cub, cuticula of cirrus. sg, shell-gland. 



D, dorsal. sr, sperm-reservoir. 



g, ganglionic ring. t, testes. 



ivs, second vesicula seminalis. us, uterus-sac. 



lev, lateral excretory vessel. iLt, uterine tube. 

 Imp, longitudinal muscles of paren- V, ventral, 



chyma. v, vagina. 



mev, median excretory vessel. ve, vas efferens. 



n, nucleus. vf, vitelline follicles. 



ns, nerve strand. 



Plate V. 



Fig. I. Scolex and first three proglottides, X 32. 



Fig. 2. I2th, 13th and 14th proglottides, X 8 



Fig. 3. Proglottides 20 to 25, inclusive, coronal view, X 8. 



Fig. 4. Same, laternal view, showing disappearance of auricular appen- 

 dages, X 8. 



Fig. 5. Young "scolex," showing beginning of proglottidation, X 16. 



Fig. 6. Smallest plerocercoid observed, X 16. 



Fig. 7. Longitudinal section through the cuticle and subcuticle: cu', 

 outer and cil" , inner layers of the cuticle; fs, foramen 

 secundarium of the excretory system; hm, basement mem- 

 brane; Icm, longitudinal cuticular muscles, X 1600. 



Fig. 8. Longitudinal section through the tip of an appendage, showing 

 the minute spines, X 1500. 



Fig. 9. Relations between m^yoblasts and muscle-fibrils: a, coronal 

 fiber; b, c and d, myoblasts of longitudinal muscles of the 

 parenchyma, X 1500. 



Fig. ID. Transverse sections of muscle-fibers: a and b, from the external 

 longitudinal series of the parenchyma; c, from the dorso- 

 ventral gi'oup, actuating the bothria;/, fibrils, X 1500. 



