3;J8 



On Cysticeecus QUADRicuiiVATUs (Rossetek). 

 By T. B. Rossetee, F.R.M.S. 



(Read Novemler J7lh, 1S93.) 



Plate XVII. 



Form of cyst, lenticular; long axis, 0*220 mm.; brcadtli, 

 0-182 mm. 



Hooks, 10 ; length, 0-028 mm. 



Habitat, Cyclops agilis. 



Locality, Mr. Gardner's Pond, Bekesbourne, near Canter- 

 bury. 



Found December, 1892. 



Among numerous Cyclops agilis taken from Mr. Gardner's 

 pond, in the j^arish of Bekesbourne, and which were the hosts 

 of the cysticercoids of Ta.nia teituirosiris — T. sinnosa, T. gracilis, 

 and T. coronula — was one which gave shelter, or rather was the 

 resting-place of the above-named Cysticercus. 



It was situated between the second and third segments of the 

 dorsal region, that is to say, just below the stomach. When 

 dissected out the cyst (Fig, I) was lenticular in its formation, 

 its long axis being 0*220 mm. and its breadth 0*182 mm. The 

 future scolex was in an immature condition, and the suckers 

 were quite indefinable. The parenchymatous tissue within the 

 cyst contained numerous fatty globules, and a very few, abnor- 

 mally so, of what Dr. 0. von Haman calls chalk bodies. The 

 depth of the fluid cavity or chamber was 0*005 mm. The 

 caudal appendage was short, and I failed to find on it the six 

 hooks of the oncosphere. 



The rostrum of the rudimentary scolex carried ten hooks, 

 whose length was 0*028 mm., root 0*016 mm., hook 0*012 mm., 

 and they are very remarkable in their formation. . Taking the 

 whole length of the hook at its back portion it consists of four 



