216 PROCEEDINGS OF THE NATIONAL MUSEUM vol.83 



Type specimen. — U.S.N.M. no. 39803; paratypes, no. 32840; all 

 collected by W. L. Jellison, of the University of Montana. 



The condition of the type specimen and of the few additional para- 

 type fragments available makes adequate description of a number 

 of details impossible, but the size and shape of the hooks, especially 

 the conspicuously long guard, constitute a character adequate for 

 specific determination. 



TAENIA LATICOLLIS Rudolphi, 1819 



Pl.\tb 19, Figures 1, 6-8 



Specifto diagnosis. — Length up to 14 cm, maximum width 3.2 mm. 

 Immature segments usually wider than long; mature segments usually 

 approximately square; gravid segments usually longer than wide. 

 Neck usuall}' distinct, sometimes obscured by contraction, usually 

 slightly narrower than greatest diameter of scolex. Genital papillae 

 only moderately prominent, located approximately in middle of seg- 

 ment margin. Suckers usually prominent, rostellum usually promi- 

 nent, about 700/x in diameter, with double circlet of 38 to 42 hooks; 

 large hooks 31)0/x to 415)U, long ; hook 400/x long with handle 195/a long, 

 blade 146/* long, guard 73/x long; small hooks 214/t to 238/t long, han- 

 dle 122/x to 134/i long, blade 134/i to 140/x long; guard only slightly 

 bifid. Ventral longitudinal excretory canals only moderately promi- 

 nent, varying widely in shape and size, up to 125/* in diameter when 

 circular in cross sections ; no other longitudinal canals demonstrable. 

 Transverse excretory canal conspicuous, up to 230/* in diameter. 



One specimen examined was 83 mm long and 2.5 mm in maximum 

 width; about 90 segments (62 immature, 10 mature, 18 gravid) ; first 

 segmentation apparent about 1.4 mm posterior to suckers; genital 

 primordia visible in twentieth to twenty-fifth segments. Scolex 1.5 

 mm in diameter; suckers 390/t in diameter, rostellum 714/* in diameter. 



Male reproductive system. — Testes approximately globular, 37/x 

 to 49/x in diameter, 180 to 250 in number, wath usual distribution 

 between longitudinal canals. No testes observed posterior to vitel- 

 larium or between lobes of ovary. Vas deferens (pi. 19, fig. 7) usu- 

 ally loosely coiled, conspicuous, sometimes occupying entire medullary 

 parenchyma from cirrus pouch to median field of segment, usually 

 curved somewhat anteriad in median field of segment, usually ex- 

 tending to center of segment. Cirrus pouch 275^ to 293/* long by 66/* 

 to 131/* wide, extending to longitudinal canals. 



Female reproductive system. — Ovaries with aporal lobe usually 

 larger, about 360/* long by 180/* wide, poral lobe about 295/* long by 

 180/* wide. Vitellarium wedge-shaped, 595/* to 655/* wide (measured 

 along transverse axis of strobila) by 60/i to 120/* long, usually extend- 



