400 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



through the aperture). Veiy short prepharynx; pharynx large, cylindri- 

 cal, 0.109 to 0.178 in length by 0.076 to 0.093 in width, overlapping 

 acetabulum. Esophagus very short or lacking; ceca extending to posterior 

 end of body; uroproct present. 



Genital pore in groove of forebody covered by acetabulum, hence 

 inconspicuous. Testes smooth, ovoid, longer than wide, tandem in pos- 

 terior half of body; separated by vitelline follicles. Cirrus sac very elon- 

 gate, extending a little over halfway between acetabulum and ovary ; con- 

 taining a swollen, tubular, slightly sinuous, seminal vesicle occupying a 

 little less than ^ total length of cirrus sac, a slender glandular portion 

 occupying a little more than the middle third, and a slender spiny cirrus 

 occupying about the terminal third. Cirrus joins metraterm a short dis- 

 tance posterior to acetabulum. Ovary ovoid, wider than long, separated 

 from anterior testis by a few vitelline follicles. Seminal receptacle present. 

 Vitellaria from shortly anterior to seminal vesicle; dorsal, ventral, and 

 lateral to ceca to posterior end of body; interrupted opposite ovary and 

 testes ; confluent between and behind gonads. Metraterm straight, spined, 

 a little over half length of cirrus sac. Eggs yellow, 58 to 65 by 31 to 36 jx. 

 Genital atrium a narrow muscular tube posterior to acetabulum, a wide 

 muscular tube dorsal to acetabulum, becoming a very thin-walled narrow 

 tube near the genital pore. 



Unpaired excretory vesicle extending to level of anterior testis whence 

 two small inconspicuous lateral tubes extend forward. These soon become 

 paired (2 on each side of the body) but remain inconspicuous until about 

 opposite the anterior end of the seminal vesicle. Here they become much 

 coiled and with veiy thick, convoluted walls and are conspicuous even in 

 total mounts. The outer (more lateral) pair becomes smaller and gradu- 

 ally disappears opposite the spiny portion of the cirrus; the median pair 

 extends to the acetabulum and becomes thin walled and inconspicuous in 

 the forebody, apparently ending near the oral sucker. 



Discussion. Although some of the unusual characters of this species 

 (e.g. the form of the oral sucker, the dorsal break in the oral spines) are 

 variable, many distinctive features are very constant. It is very different 

 from the other 2 species in the genus in its very short forebody, short pre- 

 pharynx, number and relative sizes of the oral spines, distribution of the 

 vitellaria, and length and shape of the genital atrium. The 2 pairs of 

 anterior excretory tubes seem to be unlike the single-paired condition de- 

 scribed for other species, and the thick convoluted walls of these vessels 

 are also distinctive. A uroproct is not described for either of the other 2 

 species, but this character is very inconspicuous. 



