142 Gr. A. and W. G. MacCallum, 



a mucli convoluted tube accompanied by windings of the uterus. 

 Eggs very numerous without filaments. Living on the outer surface 

 of the body or in the mouth, branchial cavity or in the body of 

 marine fishes. 



As will be seen by anyone who reads the descriptions of the 

 varioiis worms which go to make up this family together witli those 

 of a number of other forms which have been given places among 

 the Distomidae or Monostomidae, there still reigns the greatest con- 

 fusion and it seems almost impossible to set the matter straight 

 because in so many cases names have been assigned after only the 

 most raeager study of the worra and even without a Single word 

 of description. It is clear that some of the species belong not to 

 the genus Diihjmosoon but to Nematohothrium while other genera 

 have been established {KoeUikeria, WecUia by Cobbold) to receive 

 forms which had previously been named Monostomiim or Distomum. 

 Of these genera which were proposed long before Bidymosoon, Beaun 

 rejects Wedlia and retains Koellikeria. Both evidently contain forms 

 which correspond with those described as Bidymozoon and strict 

 adherence to the rules of nomenclature should force us to use one 

 of these names instead of Bidtjmozoon,. 



Cobbold in 1860 described the genus Koellikeria as follows: 

 „Sexus discretus. Corpus maris filiforme antrorsum 

 clavatum, retrorsum sensim attenuatum. Os acetabu- 

 liforme orbiculare. Acetabulum ventrale sessile. 

 Apertur a genitalis inter os et acetabulum. Corpus 

 feminae antrorsum filiforme clavatum, retrorsum 

 subito in c r e s c e n s , r e n i f o r m e. A p e r t u r a g e n i t a 1 i s i n t e r 

 OS et acetabulum. K. filicollis Cobb. =^ B. okenii Ivoell., B. 

 fiUcolle VAN Beneden, Monost. füicolle Rud. 



The same author described the genus Wedlia as follows, the 

 description showing that it is like Koellikeria except in having only 

 one sucker. 



Wedlia: Corpus inerme, reniforme, lobatum; aliquando 

 antrorsum attenuatum, apice incrassatum clavatum, 

 retrorsum subito increscens. Os terminale acetabuli- 

 forme. Acetabulum ventrae mullum. Androgyna (?) 

 apertura genitale infra os. Oviparum, o vulis non oper- 

 culatis, avium incola et in cavo branchiarum piscium 

 marinarum gemmatim in folliculis inclusum. 



