2 THE ROYAL SOCIETY OF CANADA 



sac; a large, almost spherical vesicula seminalis immediately postero" 

 dorsal to the cirrus-pouch. Latter spheroidal in shape, simple in structure' 

 containing "ductus ejaculatorius," a second vesicula seminalis and a 

 cirrus lined with cuticle provided with small stout spines and a series of 

 circular muscles. Vagina courses ventrally and expands within the "genera- 

 tive space" to form a well-developed receptaculum seminis, sharply se- 

 parated from the very small and short continuation (the spermaduct) 

 which unites with the oviduct to form the fertilization-duct ("Befruch- 

 tungsgang"). Sphincter vaginae and oocapt present. Uterus divided into 

 two portions, a much-coiled proximal thin-walled tube, the uterine-tube 

 ("Uteringang") and a large uterine-sac ("Utershôhle") which when gravid 

 occupies almost the whole of the middle of the proglottis. Eggs with oper- 

 cula. Life history as yet unknown. 

 Species: globuliforme Cooper, {globulus, a bead; forma, shape or form). 



With the characters of the genus. See more detailed description to 

 appear later. Habitat : Pyloric portion of the intestine of Amia calva, L. 



From the foregoing description one would be inclined to place the 

 worm in the family, Dibothriocephalidae Luehe 1902, of the order, 

 Pseudophyllidea Carus. In fact the arrangement of the reproductive 

 organs, excepting the uterus, strongly resembles, on the whole, those 

 of Dibothriocephalus latus Linn, as described by Sommer and Landois 

 (72). Luehe ('02) has indicated that the following are important 

 characters of the family: "Cirrus unbestachelt, mit zerklûfteter 



Cuticula Die beiden Flâchen der Proglottidenkette (ab- 



gesehen von den Genitalôffnungen) gleichgestaltet. Receptaculum 

 seminis gebildet von einer lokalen Erweiterung der Vagina nahe deren 

 inneren Ende, welche in der Regel gegen den Samengang (Endab- 



schnitt der Vagina) scharf abgegrenzt ist Eier mit Deckel 



âhnlich den Eier der Fascioliden." The uterus, on the other hand, 

 is described as: "ein langer, mehr oder weniger stark gewundener 

 Kanal, hâufig in der sogenannten Rosettenform, kann lokal mehr 

 oder weniger stark erweitert sein, bildet jedoch niemals eine 'Uterus- 

 hôhle,' welche als einheitlicher Hohlraum den grôssten Teil des 

 Querschnittes reifer Proglottiden einnimmt." Apparent exceptions 

 to this description of the uterus are seen in Scyphocephalus Riggb. 

 and Bothridium Blainv., but in these genera there is no true division 

 into a uterine tube and a uterine sac, the large cavity distended with 

 eggs, especially in the latter, being composed of the coils ("Rosetten- 

 form") which are more distinct in earlier stages. Thus Haplobothrium, 

 in spite of its resemblance in many other respects to a few genera of 

 the sub-family Dibothriocephalinae Luehe, differs in two very impor- 

 tant points from the members of the Dibothriocephalidae, viz., the 

 cirrus is provided with minute yet distinct and numerous spines, and 

 the uterus is divided into two definite portions, a uterine tube and a 

 uterine cavity. Some readers may be inclined to think that this 



