642 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 40. 



Type-specimens. — United States National Museum, Helmintho- 

 logical collections, No. 7319, collected by Mr. J. Alden Loring, July 4, 

 1909, at N'garri, Narok River. 



As to the taxonomic position of SpJiyroncotsenia uncinate,, the 

 presence of hammer-shaped hooks on the rostellum is a character 

 which by itself may be considered sufficient to establish the species 

 in the family Davaineidse, although heretofore no species of this family 

 has been known which possesses more than three rows of hooks on the 

 rostellum. Of the three subfamilies of the Davaineidns, Ophryocot- 

 ylinse is excluded from consideration on account of differences in the 





/lornm. 



Fig. 6.— Sphyroncot^nia uncinata. Transverse section through genital pore, cirrus pouch, 

 and neighboring structures, cl., genital cloaca; c. p., cirrus pouch; ex., excretory vessel; 

 1. 71., lateral longitudinal nerve; t. 111., transverse muscles; vag., vagina; v. d., vas deferens. 

 Enlarged. 



rostellum, and the absence of para-uterine organs. The subfamily 

 Davaineinse is also excluded on account of the absence of para- 

 uterine organs. The third subfamily, Idiogeninse, is characterized 

 especially by the presence of a single set of reproductive organs in 

 each segment, a sac-like uterus more or less lobed or much branched 

 which is not persistent and from which the eggs finally pass into a 

 para-uterine organ. SpJiyroncotsenia uncinate possesses all of these 

 characters and may therefore be placed in the subfamily Idiogenmse. 

 Two genera have heretofore been recognized in this subfamily, 

 namely the type genus, Idiogenes Krabbe, 1868, and Chapmania 

 Monticelli, 1893. 



