.70 Roosevelt Wild Life Bulletin 



Xineteen species of Gastropoda, including 221 individuals, were 

 examined and of these the following species yielded no internal 

 parasites : Amnicola limosa (Say), 20 individuals examined; Ancylus 

 parallelus Haldeman. i individual examined; Bytliinia tentaculatd 

 (Linn.). 17 individuals examined; Lymnaea columella Say, i 

 individual examined; Lymnaea haidermani Binney, 10 individuals 

 examined; Planorhis hirsutus Gould, 10 individuals examined; 

 Planarbis parznis Say, 3 individuals examined; Valvata tricarinata 

 Say. ;^^ individuals examined; Vnnpera contcctoidcs Binney, 

 3 individuals examined. 



The following Gastropoda contained parasites : 



Campomela integrum (Say). Three snails were examined, of 

 which the livers of two were infected with a tailless Trematode 

 lars-a belonging to the genus Agamodistomum. The worm is fusi- 

 form in shape and about 1.25 mm. long by 5 mm. wide. The worms 



were not numerous. 



Goiiiobasis Vwcscens (Menke). Twent}--three snails were 

 examined, the livers of six of which were infested wdth a small 

 number of sporocysts and cystocercous cercariae of large size and 

 similar to Cercaria anclwroides Ward. The sporocysts are rather 

 regularly fusiform in shape and from one to two milHmeters in 

 length, and contained three or four cercariae each. The free cer- 

 cariae are about 3 mm. in length, of which the body measures i mm. 

 The tail is flat with the anterior half covered with large papillae, and 

 terminates in a pair of flat blades, each .5 mm. in length, which pro- 

 ject at right angles. Similar cercariae have been taken previously 

 in four localities in the eastern and central part of this countn,-. in 

 three of which places it was found free-swimming, moving about 

 actively with the tail in advance. It was not found free-swimming 

 in Oneida Lake and when taken from the livers of the snails appeared 

 ver\- sluggish and without definite swimming motions. 



Lymuaca catascopium Say. Ten snails were examined, the 

 livers of six of which were infested with two species of larval Tre- 

 matodes. One of these species is a xiphidiocercaria about .2 mm. 

 long, with a slender tail considerably shorter than the body. The 

 other species is a holostomid belonging to the larval genus Tctra- 

 cotyle and similar to that taken from Lymnaea emarginata. 



Lymnaea emargiiiata Say. Five snails were examined, the livers 

 of three of which were heavily infected with holostomids of the larval 

 genus Tetracotyle, similar to those found in Lymnaea catascopium. 

 These lanae belong to some species of the genus Strigea which para- 

 sitize fish-eating water birds. Adult worms of this genus have been 

 taken in the herring gull and the great blue heron on Oneida Lake. 

 These interesting larvae are pear-shaped and measure .26 mm. by 

 .19 mm., the oral sucker and sucker-like depressions being at the 

 larger end. Two growth sizes were observed, the smaller being the 

 one just described. The larger one has a large circular forward por- 



