STUDIES ON THE DIGENETIC TREMATODKS. 425 
extends beyond the ventral sucker. The latter also describes 
the ovary as midway between ventral sucker and anterior 
testis, and the ova as not numerous—tento twenty. In this case 
it is apparent that a different species is under consideration, 
for in the European form, according to Olsson’s observation, 
which I confirm, the cirrus-pouch does not extend beyond the 
centre of the ventral sucker. For this American species I 
propose the name Stephanophiala transmarina (= 
Crepidostomum laureatum Stafford, 1904, = ? Dis- 
tomum laureatum Linton, 1895) from Salvelinus fonti- 
nalis Mit. and Salmo mykiss. 
Stafford mentions two other varieties, one from Perea 
flavescens, the other from Necturus maculatus, and 
these will possibly prove to be further species of the genus 
Stephanophiala. With regard to Crepidostomum 
cornutum (Osborn),! it is doubtful if this species can be 
included in the genus Stephanophiala. ‘The small size of 
the ventral sucker is against this and brings it into closer 
relation with Acrodactyla. The species, however, is not 
yet sufficiently well known for its position to be determined. 
If it cannot be included in the genus Acrodactyla it may 
require to be considered as the type of a distinct genus. 
The natural sequel to the foregoing classification would be 
the formation of a family Bunoprrip# along the lines indicated 
by Heymann in his definition of the sub-family BunopErina», 
but such a step would be undoubtedly premature, if not 
erroneous. It must be regarded as very doubtful if the 
STEPHANOPHIALIN® are so closely related to the Bunopgrinm, 
as has been hitherto considered. Most indications seem to 
point to a further separation of these two sub-families, and 
a nearer approximation of the SrePHANOPHIALIN® to the 
ALLOCREADIINE. This, however, must be a matter for future 
determination. 
1 *Science,’ xv (1902), p. 573. 
