Bull. U. S. F. C. 1899. (To face paee 492.) 
Plate XXIV. 
262. Tetrarhynchus bisulcatus , continued. Section of parasite, cut 
longitudinally, in submucous coat of stomach, x 50. 
263. Transverse section through muscular bulb of proboscis, x 400. 
n, Nerve cells; r, retractor of proboscis. 
264. a, Hooks in retracted proboscis of encysted parasite, • 800; b, c, 
groups of nerve cells lying beside contractile bulb, x 400; d, 
same, x 750. 
265. Transverse section of dorsal muscles of Rhombus triacon thus with 
cysts containing Shynchobothrium sp. x 30. (See 255-256o.) 
266. Dibothrium crassiceps Rudolphi, from intestine of Merlucdus 
bllinearis. Marginal view of head, x 40. 
267. Lateral view of head, x 40. 
268. Posterior end of strobile, x 40. 
269. Dibothrium angustatum Rudolphi, from intestine of Merluccius 
bilinearis. a, Head, x 50; 6, median segments, x 50; c, poste- 
rior segments, x 30. 
