372 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



subglobular, 0.059 to 0.087 long by 0.056 to 0.071 wide; esophagus about 

 same length as pharynx, its anterior portion muscular and thick walled ; 

 intestinal bifurcation about midway between suckers ; ceca uniting not far 

 from posterior end ; anus lacking. Genital pore to the left, opposite ante- 

 rior half of esophagus. Testes tandem, or very slightly oblique, close to- 

 gether, smooth, wider than long, in posterior half of body. Testes were 

 lacking in both specimens from Malacoctenus zonifer. Seminal vesicle 

 tubular, coiled between acetabulum and intestinal bifurcation, only slight- 

 ly overlapping acetabulum. (In one specimen from Bathygobius what 

 seemed to be the seminal vesicle extended slightly posterior to the ace- 

 tabulum.) Cirrus sac thin walled, between pore and left cecum which it 

 overlaps but does not overreach, containing a sinuous ductus ejaculatorius 

 and delicate cirrus (fig. 45). The narrowing seminal vesicle apparently 

 not constricted as it enters the cirrus sac. Ovary small, ovoid, wider than 

 long, to the right (sometimes median), close in front of anterior testis; 

 seminal receptacle lacking; uterus pretesticular, may overlap left cecum 

 slightly ; metraterm thin walled, not quite so long as cirrus sac ; eggs 48 to 

 51 by 26 to 32 p.. Vitellaria from intestinal bifurcation or esophagus re- 

 gion in sides of body to posterior end, lateral to ceca in anterior half of 

 body, then, beginning at level of ovary, ventral and lateral to ceca, con- 

 tiguous behind testes and behind cecal union. Excretoiy vesicle to level of 

 ovary. 



The name tropicum refers to the tropical distribution of this species. 



CotJiparisons. Of the 10 species named in the genus Coitocaecum, the 

 following 8 have vitellaria anterior to acetabulum; C. anaspidis Hick- 

 man, 1934; C. diplobulbosum Ozaki, 1929; C. latum Ozaki, 1929; C. 

 jnacrostomum Pigulewski, 1931; C. orthorchis Ozaki, 1926; C. ovatum 

 Pigulewski, 1931; C. plagiorchis Ozaki, 1926; C. unibulbosum Ozaki, 

 1929. In Ozaki's 1929 key to species, C. tropicum keys to C. orthorchis, 

 while in Hickman's 1934 key it keys to C. anaspidis. C. orthorchis is re- 

 described and figured by Yamaguti, 1938. C. tropicum differs from it in 

 much smaller size, much smaller eggs, somewhat more anterior genital 

 pore, somewhat smaller cirrus sac, and entirely lateral vitellaria in the 

 forebody. It differs from C. anaspidis in smaller size, much smaller eggs, 

 more tandem testes (perhaps a variable character), relatively larger phar- 

 ynx, and entirely lateral vitellaria in the forebody. All 3 species are re- 

 m.arkably alike when one considers the differences in hosts and localities. 



Discussion. Reference should be made here to the collections from 

 blennies at Charles Island and from Opisthognathus scops from the same 



