Specimens of Echinorhynchus baeri collected from Salmo trutta in Turkey and proboscis hook rows of specimens of E. sevani and E. baeri, respectively, collected from Salmo ischchan in Lake Sevan, Armenia. 3. A male specimen. Note the unique amoeboid, lobulated giant nuclei in the long lemnisci (arrow), the prominent retractor muscles, and the near contiguous ovoid-elongate testes. Proboscis is usually bent ventrad. 4. A gravid female with typically long lemnisci. The reproductive system is obscured by eggs. 5. The female reproductive system. Note the very long and slender uterus and the longitudinal bulge near its distal end (upper arrow). Also note the laterally extending uterine glands at the base of the uterine bell (lower arrow). 6. The proboscis of the male specimens in Fig. 3. Note the uninucleated round cells (arrow). 7. A ripe egg with prominent polar prolongation of the fertilization membrane. 8. A ventral row of proboscis hooks from a male specimen. Note the lack of root manubria anteriorly and the gradual development of manubria with decreasing size of roots posteriorly. 9. Lateral view of hooks of E. sevani after Dinnik (1932) showing variable manubriation in all hook roots “A = first two hooks. B & C = middle hooks, D & E = last two hooks of the vertical row.” Measurement bars were not provided. 10. Lateral view of hooks of E. baeri after Kostylew (1928) showing the absence of manubria in all hook roots and the virtual absence of roots of the basal hook; measurement bars were not provided.