Ai'.T. 2-1 TWO SPECIES OF TEEMATODE WORMS PRICE 7 



distribution of the uterine coils. In the genera of Nudacotylinae 

 the genital pore is postuterine and to the side of the median line, 

 and the uterine coils extend a considerable distance beyond the lateral 

 limits of the ceca, while in the Notocotylinae the genital pore is 

 preuterine and median in position, and the uterine coils are confined 

 for the most part within the lateral limits of the ceca. 



Moiiostomhum sphargidis MacCallum, 1921, is considered a synonym 

 of Astrorchis renicapite (Leidy). A comparison of specimens 

 (U.S.N.M. No. 8094) of this species from the MacCallum collection 

 with specimens from the Leidy collection shows no essential differences. 



Linton (1910) described two trematodes, Barlsovium er-ubescens, 

 new genus and species, and Hlmmomum. cmiclidvlwin^ new genus and 

 species, which unquestionably belong to the Pronocephalidae. So far 

 as it is possible to determine from the descriptions of these trema- 

 todes, there appears to be no justification for regarding these species 

 as belonging to separate genera and Himasomuon is considered a 

 synonym of BaHsomum, H. candidulum Linton, therefore, becoming 

 Bansoinunn cmididulum (Linton). The genus Barlsomwm is appar- 

 ently closely related to GlyphicepJiaJus Looss and Epibathra Looss, 

 the principal difference between these genera being in their excretory 

 systems. In Barisomwni the limbs of the excretory vesicle unite at 

 the anterior end of the body, in Glyphlcephalus the limbs do not 

 unite anteriorly, and in Epibathra the limbs do not unite but are 

 connected by means of a number of transverse anastomoses. Whether 

 the excretory system is a character of sufficient importance to justify 

 the separation of these otherwise identical genera is a matter of per- 

 sonal opinion. Further investigation is necessary before this point 

 can be definitely settled and for the present these genera may be 

 regarded as valid. 



In considering the classification of this family certain difficulties 

 arise in regard to the validity of the name Pronoceplialidae. Looss 

 (1899) proposed the subfamily Pronocephalinae, but he designated 

 no type genus, although he apparently intended the genus Prono- 

 cepTialus as such, since he bases the name on it and gives the diagnosis 

 of this genus immediately following tlie subfamily diagnosis. In 

 1902, he elevated this subfamily to the rank of family and designated 

 GlypMcephalus as type genus. This is in violation of article 4 of 

 the International Kules of Zoological Nomenclature which says: 

 "The name of a family is formed by adding the ending idae. the 

 name of a subfamily by adding inae^ to the stem of the name of its 

 type genus." Two solutions of this problem, therefore, appear pos- 

 sible: (1) Pronocephalus is intended as type genus of the subfamily 

 Pronocephalinae and the elevation of this subfamily to the rank of 

 family retains Pronocephalus as type in spite of the later designation 



