TREMATODES FROM FISHES — ^LINTON 



31 



behind the other, close to the right side, or nearly opposite each other 

 near the median line. Usually the first testis is behind the level of 

 the ventral sucker, but in some cases it is crowded forward until its 

 posterior edge is on a level with the ventral sucker. The ovary lies 

 in front of the testes, and is usually near or in contact with one or 

 both of the testes. It may be larger or smaller than a testis, or it 

 may be about the same dimensions. Usually the testes are about the 

 same size, circular, oval, subtriangular, to oval-elliptical in outline. 

 The vitellaria, consisting of about 32 follicles, extend across the body 

 from side to side, in some cases a short distance back of the anterior 

 sucker, in others crowded forward so as to overlap the anterior 

 sucker. The follicles extend but a short ways, if at all, along the 

 sides. The uterus is very voluminous and may fill the body from 

 the posterior end to the anterior sucker, thus more or less obscuring 

 the anatomy. The eggs are small, about 0.015 by 0.009 mm. in bal- 

 sam ; shells thin, and usually more or less collapsed. No satisfactory 

 formula can be given to describe the relative positions of the geni- 

 talia. For example, the anterior end of the cirrus pouch is, in some 

 cases, about at the level of the posterior edge of the second testis, and 

 therefore far back of the ventral sucker. In other cases the anterior 

 end of the cirrus pouch may be in front of the first testis and in front 

 of the ventral sucker. 



In some there is a distinct cap overhanging the anterior sucker 

 (pi. 18, fig. 246). In others the cap is reduced to a buttonlike proc- 

 ess, and in still others there is no trace of it. In some, also, the 

 anterior sucker appears to be retracted (pi. 18, fig. 247). 



Table 9. — Measurements of six specimens of Prosorhynchus gracilescens, in 



balsam 



Measurement 



Length 



Breadth, anterior end 



Breadth, middle.. 



Breadth, near posterior end 



Anterior sucker, length 



Anterior sucker, breadth 



Diameter of ventral sucker. 



Mm. 

 0.54 



.45 



' No. 6, shown in pi. 18, fig. 247, represents an extreme case of contraction. 



The above account is based on material from the garfish {Stron- 

 gylura marina). 



Hosts. — Silversides {Menidia notata)^ kingfish (Menticiri'hus) , gar 

 {Strongylura marina), goggler {Trachurops cnimenophthalma) . 



Record of collections. — One, immature, collected August 26, 1904, 

 from silversides. Dimensions, life: Length 1.4 mm..] breadth 0.55 



