Three new Trematodes founcl principally in Black Bass. 479 



spot". There are a number of marked differences between Crypto- 

 gonimus and CaecincoJa most strikiug of which is tlie possessio!! by 

 the forüie!' of two ventral suckers and of "eyes". The position and 

 comparative size of tlie oi'gans within the two fliikes is very simihir. 

 OsBORN having iised the possession of two ventral suckers as one 

 of the Chief characteristics of bis genus w^ould exciude our specimen, 

 although we can not get rid of a suspicion tliat the two are identical. 

 Caecincola rese!nbles, in its general appearance, the genus Gymno- 

 phalhis of Odhner (5). This fluke has, however, a simple ova!y, 

 a laige pars prostatica and the yolk glands near the center of the 

 body. The exterual form of Caecincola is, in live speci!nens. fairlj^ 

 constant but in those w^hicli have been killed and mounted there is 

 apt to be a Variation, caused by a constriction of the body in the 

 praepharyngeal regiou. This is shown to a slight degree in the 

 figure. The enti!-e body is covei^ed with miuute spiiies visible only 

 under a high power. These run diagonally around the body and 

 where the rows cross each other little spineless areas are found; 

 these are neaidy Square. The !nouth is of medium size, the oral 

 sucker, diameter 0.14 mm, is nearly equal to the body at its widest 

 part. The dia!neter of the acetabulum is 0,05 !n!n. The !nouth 

 leads into a long praepharynx 0,06 mm in length, which passes into 

 a well developed pharynx 0,045 nun in length. The Oesophagus 

 follows with a length of 0,035 mm, and is of eqiial thickness to the 

 praepha!ynx. Just anterior to the acetabulum the Oesophagus passes 

 into the two intestinal caeca which extend slightly beyond the middle 

 of the body reaching the anterior edge of the festes. Each caecum 

 is Wide, much wider than the Oesophagus, its wall for!ned of a Single 

 layer of large cells. At either side of the praepharynx are a number 

 of large glandulär cells which apparently pass forward to open into 

 the mouth region. The cerebral ganglia (Fig. 1, hr) are very large, 

 one either side of the praepharynx. They are connected by an 

 oesophageal commissure which crosses the praepharynx. The only 

 other traces of the nervous System which we found were two nerves 

 passing foi'word, one from each ganglion. 



The excretory vesicle (Fig. 4) is large and when distended 

 occupies a great part of the body. The excretory pore is terminal, 

 opening into a short, narrow, thick-walled duct which leads into 

 the !nedian stem of the vesicle. This !nedian stem extends forward 

 about one-third the length of the body; it is, wdien distended, large, 

 but narrower than either lateral stem. The eutire vesicle does not 



32* 



