4 RECORDS OF THE AUSTRALIAN MUSEUM. 



II. — Description of the Species. 



TiENIA TUBERCULATA, Krefft. 



[From the White-eyed Duck or Widgeon (Aythya 

 australis, Gould).] 



(Plate i.) 



1 propose first to describe as well as the macerated material 

 will allow, the anatomy of Tamia tuberciilala, Krefft, and 

 then to discuss its systematic relationships. The imperfeco 

 condition of the specimens must he taken into consideration, 

 especially as this account is based entirely on Krefft's type 

 material. The main facts relating to the worm as given by 

 Krefft 5 are as follows : — Length seldom exceeding forty-two 

 inches ; average breadth one quarter inch, but may reach a half 

 inch ; head small; neck long; anterior end of the strohila very 

 variable ; no trace of the presence of suckers and rostelluni ; 

 segments very narrow in anterior part of the chain ; tubercles on 

 the posterior segments ; double genital papilhe in each segment ; 

 cirrus spiny and hell shaped ; eggs circular and without hooks. 



A glance at his figures will show that the material was in a 

 poor state of preservation at that time, and its condition 

 has not improved since. His account may accordingly be 

 disregarded. 



None of the scolices examined allow of the recognition of 

 much detail. They are small and somewhat rounded and do not 

 project at all laterally, but on the contrary, the scolex is tlie 

 narrowest part of the strobila, being about 0*145 mm. in 

 breadth in the region of tlie suckers. The latter are very weak 

 structures when compared with the size of the parasite, being 

 about 055 mm. in diameter. Their openings are directed 

 antero laterally. 



A rather long, delicate eversible rostellum is present and is 

 surrounded by a single circlet of ten hooks. These are very 

 small, being about 0018 in length. The dorsal root is relatively 

 long and rodlike, tlie ventral root short and rounded, and the 

 claw small. The whole series is so closely clustered in the 

 .scolices examined that it is difficult to make out the exact form 

 of each hook. 



6 Krefft— hoc. cit., pp. 215-16. 



