AKT. 18 THE TREMATODE FAMILY SCHISTOSOMIDAE PRICE 25 



Tyye specimens. — United States National Museum Helminthologi- 

 cal Collections No. 25169; paratype No. 27888; collected by Dr. E. A. 

 Cliapin, January 20, 1923. 



This trematode appears to have closer affinities with species of 

 Aitstrohilharzia than with those of any other genus. There are some 

 characters in this species which differ from A. terrigalensis^ type of 

 Austrobilharzia, to such an extent that the writer hesitates to place 

 his species in this genus; a new genus, Microhilliarzia, is therefore 

 proposed for it. In proposing this genus the writer realizes that the 

 characters given in the diagnosis may be of specific rather than of 

 generic value, but in order to include this species in Austrohilharzia^ 

 or in any of the other genera, it would be necessary to emend the 

 generic diagnosis more or less extensively; this is regarded as inad- 

 visable until more material is available for study. 



BiLHARZlELLiNAE, new subfamily 



Suhfamiily diagnosis. — Schistosomidae : Male and female similar in 

 form, either flattened or threadlike. Suckers present or absent. Gynae- 

 cophoric canal absent or imperfectly formed. Paired intestinal ceca 

 short ; common cecum long, with or without lateral dendritic branches. 

 Testes numerous and situated along the course of the common cecum. 

 Uterus short and containing a single egg. 



Type genus. — Bilharziella Looss, 1899. 



KEY TO THE GENERA OF BILHARZIELLINAB 



1. Body cylindrical or nearly so 2. 



Body flattened 3. 



2. Female unknown ; posterior end of body threadlike, middle portion wider 



than either the anterior or posterior portions ; no gynaecophoric canal ; 



suckers present Trichobilharzia, p. 29. 



Male and female very long and slender ; gynaecophoric canal reduced to a 

 short groove in the anterior part of the body ; suckers absent. 



Gigantobilharzia, p. 30. 



3. Suckers present; common cecum without lateral dendritic branches. 



Bilharziella, p. 25. 

 Suckers absent; common cecum with short, lateral dendritic branches. 



Dendritobilharzia, p. 28. 



Genus BILHARZIELLA Looss, 1899 



Generic diagnosis. — Bilharziellinae : Both sexes Avith the posterior 

 part of the body distinctly flattened. Female shorter than male. In- 

 testinal ceca united posteriorly at or near equator of body; common 

 cecum long, without lateral branches, and extending in a zigzag man- 

 ner to posterior end of body. Male genital opening situated on left 

 side of body a considerable distance caudad of acetabulum. Cirrus 

 pouch present, containing the prostate and the ejaculatory duct. 



