400 T. B. ItOSSETER ON HYMEN OLEPIS ACICULA SINUATA, 



The foregoing Table will readily prove to the student in Avian 

 Helniinthology that however much the cephalic hooks of each of 

 these worms resemble each other in shape and dimensions, in all 

 other respects the two worms under consideration are totally distinct 

 species; and consequently a new specific name must be allocated 

 to the new one. First, however, it must be dealt with generically. 



I am at all times averse to overburdening a family with a 

 superabundance of genera. Simply because one has an isolated 

 specimen of a known group with some unusual (or possibly 

 aberrant) structural peculiarities, such as the ribbed vestibule 

 and intercostal membrane ; and the replacement of the normal 

 male copulatory organs by a simple canaliculus genitalis in the 

 present specimen, it does not necessarily follow that one is 

 warranted in classifying it under a new genus. 



From the fact of this worm possessing but two globose testes 

 situated sub-median in the segments one would feel induced to 

 place it in the genus Diorchis; but in addition to the want of 

 a male copulatory organ, its internal anatomy and formation 

 of the segments agree so accurately with the diagnostic characters 

 of Hymenolepis, Weinland, that I cannot do otherwise than place 

 it in that genus. As a justification for so doing I maintain that 

 this method of fructification, hitherto unrecorded in the genus 

 Taenia, should be no bar to its entrance into the genus Hymeno- 

 lejns, especially when we consider as a precedent that von Linstow 

 has already, in spite of what I consider equally if not more 

 aberrant physiological conformation, placed his new species 

 bilateralis in the genus Hyme?iolepis, admitting, as he does, that 

 " Die Vagina verlauf t ventral vom Cirrus-beutel Ein. Recep- 

 taculum seminis fehlt. Eier waren noch nicht vorhanden :! 

 (Uelminthen der Eussischen Polarexpedition 1900-3. Dr. 0. 

 von Linstow, 1905). 



Thus if in the opinion of such an authority in helniinthology 

 as O. von Linstow the absence of such an organ as the recep- 

 taculum seminis does not necessarily demand the transmission 

 of a species from one genus to another, neither in my opinion 



