NO. 14 MANTER : DIGENETIC TREMATODES OF FISHES 359 



Straight. P. symmetrorchis is different in body shape, sucker ratio, more 

 posterior testes, and unlobed ovary. P. monocanthi has a more lobed 

 ovary, more anterior uterus, and smoother testes. 



Pseudocreadium spinosum, new species 

 (Plate35,figs. 30, 31) 



Host: CaulolatiKis sp. (whitefish) 



Location : Intestine 



Locality: James Island, Galapagos 



Number: Large numbers were collected from a single host. 

 In the same fish were Lecithochirium microstomum 

 and Choanodera caulolatili. 



SPECIFIC DIAGNOSIS OF PSEUDOCREADIUM SPINOSUM 



Sides of the thin, flattened body are curled over ventrally especially 

 along the lateral edges and sometimes to a lesser degree along the pos- 

 terior edge. If flattened out, the body would be as wide as long or even 

 wider, but this condition is rarely seen. Length 0.592 to 1.053. A speci- 

 men 0.510 long contained no eggs. Body width measurements (0.562 to 

 1.053) are usually not precise because of the ventral folding of the lat- 

 eral edges. Both ends are broadly rounded ; anterior end likely to be more 

 truncate. Spines conspicuous in anterior half of body and extend pos- 

 teriorly almost to the end of the body. Suckers weakly muscular. Oral 

 sucker circular, subterminal, a short distance from anterior end, 0.071 

 to 0.116 in diameter; acetabulum near middle of body or slightly an- 

 terior to middle, circular or subcircular, 0.107 to 0.168. Sucker ratio 

 approximately 3 :4. Forebody slightly more than ^ body length. Pre- 

 phar}'nx wide; pharynx globular (0.042 to 0.068 in diameter) ; esopha- 

 gus short. Ceca unbranched, not undulating, curving backward distant 

 from sides of body, passing closely outside testes and curving a short dis- 

 tance medianly just posterior to testes, ending blindly. Ceca very incon- 

 spicuous and partly covered by vitellaria. Genital pore to left of midline 

 about midway between suckers, opposite or just median to left cecum. 

 Testes symmetrical, just posterior to acetabulum, intercecal, separated by 

 ovary and uterus, longer than wide with the long axis extending diagonal- 

 ly backward, outline smooth to definitely lobed. Cirrus sac elongate, cla- 

 vate, large, extending from genital pore diagonally backward to overlap 

 the right half of acetabulum. In a 1.012 specimen the cirrus sac was 0.310 

 by 0.088. It contains a subtriangular seminal vesicle, a bipartite prostatic 



