Bull. U. S. F. C. 1899. (To face page 492.) 
Plate XV. 
185. Ascaris, sp. immature, from Lophius piscatorius. Ventral view of 
head, x 300. 
186. Upper lip. X 300. 
187. Posterior end, lateral view, x 300. 
188. Filaria rubra Leidy, from Centropristes striatus. Lateral view of 
head, x 75. 
189. Optical section of same, x 200. 
190. Opposite side of same, x 200. 
191. Posterior end. x 200. 
192. Filaria serrata sp. nov., from Phycis tenuis. Head and anterior 
end of female, x 300. 
193. Head of male, x 300. 
194. Posterior end of same, showing longitudinal serrate rows of 
plates, x 240. 
195. Copulatory spines, x 240. 
196. Plan of anal papillse. 
197. Spiroptera pectinifer sp. nov., from Sphyrna zygsrna. Head of 
male, x 300. 
198. Posterior end of same, lateral view, x 65. 
