297] NORTH AMERICAN P0LYST0MID.1E—STUXKARD 17 



eggs. The form maturing on the gills of the tadpole has a spherical 

 testis, lacks external vaginae and a long coiled uterus, and has a small 

 uterine cavity in which a single egg develops. Halkin and Goldschmidt 

 have investigated the early stages in this form, but the writer has been 

 unable to find any reference to work on the later larval stages. The 

 findings of Zeller are so unusual that one is led strongly to suspect he 

 confused two different species. 



The descriptions of P. ocellatum by Rudolphi (1819) and Kuhl and 

 Hassalt (1822) are very brief ; that by Willemoes-Suhm (1872) contains 

 one plate, and Looss (1885) figured only the structures at the distal ends 

 of the excretory tubules. 



The description of P. oblongum Wright (1879) contains sufficiently 

 detailed information for a specific diagnosis and is illustrated by three 

 figures. Stafford (1905) reported P. oblongum from the palate of Chry- 

 semys picta and the same location in Chelydra serpentina, but since 

 Wright originally described the species from the urinary bladder of 

 Aromochelys odoratus, Braun reviewing Stafford's article considered 

 the form from the oral cavity as a different species. The form described 

 by Leidy as P. oblongum, was reinvestigated by Goto (1899) and proved 

 to be a different species from that described by Wright, but the material 

 lie reports was in such a poor state of preservation that renewed study 

 was impossible and so the form must remain unknown. 



Leidy 's (1888) description of P. coronatum is so brief that it is al- 

 most valueless ; a type specimen mounted as a toto preparation has been 

 available for the present study and many additional points of structure 

 are added to the original description. 



P. hassalli was described by Goto (1899) from the urinary bladder of 

 Cinosternum pennsylvanicum and has been collected by the writer from 

 the urinary bladder of Aromochelys odoratus, A. carinatus, and Chelydra 

 serpentina, as well as from Cinosternum pennsylvanicum. Additional 

 data correct and supplement the description of Goto. 



Johnston (1912) described P. bidliense from the urinary bladder of 

 two species of Hyla from New South Wales, Australia. Beauchamp 

 (1913) described P. alluaudi from an unknown batrachian from the lower 

 prairies of Kinangop, Africa ; the material was collected by the African 

 expedition of Alluaud and Jeannel. Stewart (1914) described P. kachu- 

 gae from the urinary bladder of the water tortoise, Kachuga lineata, at 

 Lucknow, India. 



In the genus Polystoma present evidence supports the validity of the 

 following described species listed in the order of description : 



P. intcgerrimum Frolich 1791. From the urinary bladder of frogs 

 and toads and the gills of frog larvae ; Europe. 



