PMARSE FISHES OF LAKE VALENCIA, VENEZUELA 35 



Clinostomum inter medialis Lament 



The adult of this species lives in the esophagus of the 

 cormorant, Phalacrocorax vigua Viellot. On July 27, 1918, 

 a bagre (Rhamdia quelen Quoy and Gaimard) collected under 

 a rock in the Rio Castano contained twelve encysted forms 

 distributed as follows: 5 in muscles at base of tail, 1 back of 

 head under skin, 3 under operculum, 3 under membrane cover- 

 ing floor of mouth. Two other bagres collected at the same 

 time were not infected with this parasite. The length of the 

 encysted forms was 6 to 7.5 mm. Similar encysted forms were 

 also found in an eel (Symbranchus marmoratus Bloch) caught 

 in the rocks along the shore of Isla del Euro, July 12, and in a 

 sardina, Astyanax bimaculatus (L.), collected July 20 at the 

 mouth of the Rio Bue. 



Clinostomum Cyst No. 1 



A large larval Clinostomum (Fig. 10) was taken from a 

 cyst in the muscles at the base of the tail of a gaubina, Hoplias 

 nnilabaricns (Bloch), captured along the shore of Isla del Buro, 



FIG. 10. Clinoslomum Cyst No. 1. 



July 11, 1918. (Cat. No. 7588; Helm. Coll. U. S. N. M.) It 

 measures 16 mm. in length. Probably the adult stage is 

 found in some fish-eating bird. 



Diplostomum mataguaroi, new species 



Larval forms of this species (Fig. 11) were found in cysts 

 in the peritoneum, particularly over the swim bladder, and in 

 the liver of the mataguaro, Crenicichla geayi Pellegrin. The 

 adult perhaps will be found to belong to the genus Strigea. 



Length of entire cyst, 1.54 mm.; length of larva, .92 mm.; 

 width, .48 mm. The cyst has a thin wall and there is a con- 

 siderable fluid-filled space between it and the larva. 



The body is very flat and clearly divided into two regions 

 by a constriction a little posterior to the middle. The muscular 

 oral sucker is followed by a more slender pharyngeal bulb. 



