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spicuously larger and heavier than those of remaining rows, and the only 
ones which bear conspicuous reflexed root-processes. Each root a broad, 
flattened disc, pyriform in surface view, usually approximately parallel to 
surface of proboscis wall. The thorn or hook proper attached at the 
apical or anterior end of the root, and appreciably longer than the root. 
Of this genus three previously described and one new species are 
found in North American hosts. 
NEOECHINORHYNCHUS CYLINDRATUS (Van Cleave, 1913) 
(Pl. XXIV, XXV, Fig. 15, 17, 18) 
Bodies large, aimost cylindrical except in young forms, in which the 
posterior part is gradually narrowed. Females 10 to 15 mm. long, with a 
maximum diameter of 0.7 mm. a short distance back of the proboscis. 
Males 4.5 to 8.5 mm. long, with a diameter of 0.5 to 0.7 mm. Proboscis 
slightly broader than long (0.172 by 0.150 mm.). Hooks of terminal 
circle 79 to 97 » long, 14 p» thick at base, each bearing a root 58 » long 
and 29 » broad. Hooks of middle row 37 » long and 5 » through at base. 
Basal hooks 21 to 25 » long and 3 » through at base. Embryos inside body 
of gravid female 49 to 51 » long and 15 to 21 p broad. 
Type host, Micropterus salmoides; type locality, Pelican Lake, 
Minnesota. 
Additional hosts: Anguilla chrysypa, Micropterus dolomieu, Car- 
piodes carpio. 
NEOECHINORHYNCHUS TENELLUS (Van Cleave, 1913) 
(Pl. XXIV, XXV, Fig. 16, 19, 20) 
Bodies small, attenuated. Females 3.5 to 13 mm. long; 0.6 mm. in 
maximum diameter. Males 2 to 8 mm. long. Proboscis nearly cylindrical, 
0.15 mm. long by 0.135 mm. wide. Hooks of anterior circle 90 to 110 p 
long; those of middle circle 38 »; those of basal circle about 27 ». Em- 
bryos 37 to 45 » long by 12 to 16 » broad. 
Hosts: Esox lucius, Stizostedion vitreum. 
NEOECHINORHYNCHUS EMypiSs (Leidy, 1852) 
(Pl. XXIV, XXV, Fig. 14, 21, 22, 23) 
Parasitic as adults in alimentary canal of turtles. Body much elonga- 
ted, approximately cylindrical. Females 10 to 32 mm. long with average 
width of 0.7 mm. Males about 8 to 11 mm. long by 0.7 mm. wide. Pro- 
boscis globular, length usually equaling breadth; average length 0.18 mm. 
Terminal hooks 95 to 103 » long, points usually reaching beyond bases of 
hooks of middle circle. Hooks of middle circle 49 to 59 p long; those of 
basal circle 35 to 54 ». Embryos within body cavity of gravid female 
oval, 16 by 114 p. 
Hosts: Graptemys geographica, G. pseudogeographica, Clemmys in- 
sculpta, C. guttata, “Emys serrata,’ Pseudemys elegans, P.troostu, P. 
scripta, P. concinna. 
