DISTRIBUTION OF CLINOSTOMUM MARGINATUM. 351 



to this fluke the name Distomum reticulatum in allusion to the 

 very peculiar excretory collecting apparatus. Subsequent 

 writers, including Looss himself (Looss '99), have referred this 

 worm to the species Clinostomum marginatum, and while there 

 are certain points in which it differs from C. marginatum we may 

 for the present so recognize it. This observation however takes 

 the fluke a long way out of the region in which we otherwise 

 know r the animal and seriously embarrasses the attempt to deal 

 with the geographical range of the species. In 1888 Leidy re- 

 ported a fluke from the striped bass (Roccus lineatus) which he 

 designated Distomum galactosomum. His account of the or- 

 ganization of this form touches on the form of the oral end of 

 the body and the network of collecting vessels in the body-wall, 

 tw r o features of such peculiarity that we cannot doubt but that 

 the subject of his study was none other than Clinostomum mar- 

 ginatum, which he had described in 1856 and evidently forgotten. 

 His account located the worm in a marine host for the first time, 

 unless Looss' silurid was marine. 



In 1895 MacCallum ('99), of the University of Toronto, 

 found a trematode encysted in the muscles of the frog which he 

 regarded as identical with the ones which Wright had found in 

 the fish and heron and referred to the D. gracile of Leidy. In 

 his paper of 1899 MacCallum calls the worm C. heterostomum. 



His description, while differing in some respects from my 

 material, leaves no doubt but that our material is identical. 

 I shall adopt the name C. marginatum in place of the name used 

 by MacCallum following the lead of Braun ('oo) in his revision 

 of the group. He also found the same species in the throat of 

 Ardea herodias at Danville, Ontario. 



In 1898 Linton reported and figured this species under the 

 name of D. gracile from the sun-fishes (Eupomotis pallidus and 

 Ch&nobryttus gulosus) of Kansas City, Mo. This observation 

 extended the range of the worm to a new river system, the Mis- 

 sisippi and gave us the most western point of its distribution. 

 In 1900 specimens of this fluke were found by myself at Nebish, 

 Mich., encysted in the muscular tissues of the small-mouthed 

 black-bass (Micropterus dolomieu], also, though less frequently, 

 in the muscles of the yellow perch (Percaflavescens). They were 



