On the Trematoile Parasites of British Birds. 24o 



by M. Clievreux is an attribute of tlie changed environment. 

 I do not know whether a similar colour characterizes those of 

 other open waters. As to tlie origin of Bathyonyx, however, 

 we liave so far no indication of its derivation from subter- 

 ranean ancestors ; and it appears probable, according to 

 Prof. Vejdovi^ky, whose judgment is based upon its general 

 characteristics and the details of its organization, that its 

 progenitors lived in the open waters of Lough Mask and that 

 its present characters are the result of its existence in the 

 lowest depths. My latest researches have also strengthened 

 the probability of his suggestion that a habit of burrowing in 

 mud may have enabled ISathyonyx to escape ca[jture by the 

 dredge, which skims the surface of the lake-floor. Never- 

 theless a considerable amount of mud was subjected to exami- 

 nation on each occasion, which produced nothing but some 

 N. Kochianus. 



The latter portion of Prof. Vejdovsky^s paper on the 

 synonymy of 



Gammarus Caspnry, Pratz, 

 Gammarus Kochianus, de Rougcmont, 

 Niphargus Kochianus, Vcjdovsky, 

 Nijyhargus Caspary, Wrzesniowski, 

 Niphargus Kochianus, Chilton, 



has been omitted.— Wm. F. de Vismes Kane.] 



XXXVIII. — Observations on the Trematode Parasites of 

 British Birds. By William Nicoll,M. A., B.Sc, Gatty 

 Marine Laboratory, St. Andrews. 



Towards the end of last spring I had an opportuuity of 

 examining several of the commoner species of shore-birds. 

 These were^ unfortunately, in most cases not in the best 

 condition for hclminthological investigation, as I seldom 

 received them till at least a day after they were killed, when 

 the parasites were almost always dead. The immediate 

 ap|)lication of weak formalin, however, preserved their 

 anatomical details rather well, although it rendered them 

 unfit for histological work. For this reason important 

 features in some cases are only superficially described, a 

 matter whicli I hope to improve shortly with the help of 

 better material. These obsirvatious are thus to be regarded, 

 to a certain extent at least, as merely preliminary. 



