NO. 14 MANTER : DIGENETIC TREMATODES OF FISHES 405 



Locality: James Island, Galapagos 

 Number : One specimen 



The genus Paramonorcheides Yamaguti, 1938 apparently differs 

 from Monorcheides Odhner, 1905 chiefly in its lobed ovary. The long 

 ceca and the posterior group of vitelline follicles of the present species 

 might almost be of generic value, but the species is included in Yamaguti's 

 genus. 



SPECIFIC DIAGNOSIS OF PARAMONORCHEIDES BIVITELLOSUS 



Length 0.675; greatest width (just posterior to midbody) 0.280; 

 both ends tapering slightly and rounded ; body spined except posterior to 

 testes. Oral sucker 0.102 in diameter; acetabulum 0.095 in diameter; 

 ratio almost equal, oral sucker slightly larger. Forebody 0.220 or about 

 Ys body length, rich in gland cells. Prepharynx very short or lacking; 

 phaiynx 0.049 long by 0.042 v^^ide ; esophagus very short or lacking ; in- 

 testinal bifurcation about midway between suckers or slightly nearer oral 

 sucker; ceca extending to near posterior end of body, curving inward op- 

 posite testes. Genital pore midway between acetabulum and intestinal bi- 

 furcation, submedian or slightly to the right (cirrus protruded). Testes 2, 

 about twice longer than wide, at level of beginning of posterior third of 

 body, symmetrical, far apart, near sides of body, largely or wholly extra- 

 cecal. Cirrus sac (with cirrus protruded) claviform, from pore to pos- 

 terior edge of acetabulum, largely to right of acetabulum, with ovoid 

 seminal vesicle, 2 types of spines ; cirrus with thorn-shaped spines. Ovary 

 lobed, to the right, close to right testis to which it is partly median, partly 

 anterior, ventral to right cecum ; seminal receptacle not seen ; metraterm 

 claviform, spiny, from genital pore to posterior edge of acetabulum, lying 

 to left of cirrus sac, largely dorsal to acetabulum, about same length as 

 cirrus sac; vitelline follicles arranged in two lateral groups on each side 

 divided by testes; anterior group from mid-acetabular level to testes, 

 chiefly lateral to ceca; posterior group of few follicles extending a short 

 distance posterior to testes, largely ventral to ceca. Eggs thick shelled, 

 sometimes almost spherical, 19 to 20 by 15 to 16 /a. Uterus filling most of 

 middle of body but not reaching posterior end by a short distance. Extent 

 of excretory vesicle not determined. 



The name bivitellosus refers to the double grouping of vitellaria on 

 each side of the body. 



Discussion. This species is placed in the genus Paramonorcheides 

 because of the 2 testes and the lobed ovary. It differs from both P. awa- 



