540 



FRESH-WATER BIOLOGY 



13(12) No cuticular ridge anterior and lateral to cloacal pore 14 



14 (15) Behind cloacal pore sharp V-shaped ridge. 



Gordius mlloti Rosa 1882. 



For female of this species consult 23 in this key. 

 This species was described by Montgomery as G. 

 aquaticus. Several subspecies have been distin- 

 guished. In the typical form the cuticula is marked 

 with large light spots. 



Male up to 655 mm. long, 1.3 mm. broad, equal 

 in diameter throughout; both ends obtuse; no true 

 areoles present. 



From Canada, New England, New York to South 

 Carolina; westward to South Dakota, Montana, and 

 California; south to Oklahoma, Texas and Mexico. 

 1 IG. 838. Gordius vittoli $ ; ventral view of Various Acridiidae serve as hosts for this species, 

 anterior and posterior ends of body. Magnified. Also found in Locustidae by H. G. May. 

 (After Montgomery.) 



15 (14) Cuticula behind cloacal pore without sharp, V-shaped ridge. . . 16 



Paragordius varius which might be confused here is readily distinguishable by tne trun- 

 cated anterior end. 



1 6 (17) On each side of cloacal pore a longitudinal line of hairs. 



Gordius lineatus Leidy 1851. 



For female of this species consult 28 in this key. 

 Male up to 278 mm. long, 0.6 mm. broad; very slender. Pale 

 yellow or buff in color; areoles small. Perhaps only a young 

 form of G. mlloti. Most of the specimens taken from springs. 

 FIG. 839- Gordius lineatus $ ; New Yor k, Pennsylvania, Maryland, Michigan, 

 anterior and posterior ends, and 

 surface view of cuticula. Mag- 

 nified. (After Montgomery.) 



17 (16) No line of hairs along side of cloacal pore; head not obliquely trun- 

 cated 18 



18(21) Conical spicules behind cloacal aperture. . . . . . ; :. . . . 19 



19 (20) Caudal lobes short, thick, and nearly conical. 



Gordius densareolatus Montgomery 1898. 



For female of this species consult 29 in this key. 



Male up to 290 mm. long, i .1 mm. broad. Body robust. Conical spines 

 on ventral surface of caudal lobes. Color deep chocolate, with black 

 ring about cloacal aperture. Wyoming, Montana, California. 



FIG. 840. Gordius densareolatus g . Ventral view of posterior end. 

 (After Montgomery.) 



Magnified. 



20 (19) 



Caudal lobes nearly cylindrical. 



Gordius longareolatus Montgomery 1898. 



Female of this species unknown. 



Male 115 mm. long, 0.5 mm. broad. Longitudi- 

 nally arranged elongate areoles characteristic and 

 of rounded-conical form without median groove. 

 No hairs between areoles. Color deep olive brown ; 

 tip of head white. California. 



FIG. 841. Gordius longareolatus $ ; head, tail in ven- 

 tral aspect, and cuticular areoles. Magnified. (After 

 Montgomery.) 



