144 NATURAL HISTORY SOCIETY OF DUBLIN. 



4th. The sexual apertures, which are disposed in T. solium with 

 considerable regularity on alternate sides of the successive joints, are 

 distributed in mediocanellata with exceptional irregularity of arrange- 

 ment, though always opening on the lateral aspect ; they are conspi- 

 cuous apertures that lead to a complicated, much branched, and pecu- 

 culiarly arranged sexual system. The trivial name of the entozoon is 

 derived from a median thick-walled canal or tube, which Kiichen- 

 meister considers continuous, extending from joint to joint. 



Experiments carried out by Leuckart, and repeated by Meisner and 

 others, have traced the development of this cestoid animal with much 

 success. "When calves are fed with mature j oints they soon suffer from se- 

 vere febrile symptoms, and other evidences of acute disease ; after a short 

 time their muscles are found permeated by innumerable minute hydatid 

 cysts, each containing within its cavity heads of eysticeri, resembling 

 in every particular those of the mature worm. Leuckart failed in ino- 

 culating the sheep or the pig, and other observers have confirmed his 

 statements. 



Professor Aitken, atNetley, obtained several specimens of this tape- 

 worm from soldiers, principally from men who had returned from serv- 

 ing at the Cape of Good Hope, and Professor Cobbold remarks in his 

 work on Entozoa that he was surprised on looking over the collection of 

 tapeworms at Middlesex Hospital, to find at least half their number 

 referable to this species. I believe it will be found equally common in 

 Ireland with the ordinary Tcenia solium, though the present instance is 

 the first I am acquainted with in which its characters were recognised, 

 and its claims advocated to be considered a member of our indigenous 

 fauna. 



The following paper was then read : — 



Note on " Astebidia" occubbing in Penium digitus (Beeb.) 

 By "William Aechee. 



Some time ago I made a gathering of some minute Algae from a pool 

 near Enniskerry, on the road going towards Lough Bray. Amongst these a 

 number of globular, densely-spined bodies, with green contents, conspi- 

 cuously presented themselves. The spines densely covering these were 

 very numerous, very slender throughout, and acute. The bodies them- 

 selves were mostly to be found distributed in pairs over the field of 

 view. These might easily be taken for so many zygospores of some 

 desmidian; but, much as such a structure resembled a possible zygo- 

 spore, these bodies were not like that known of any species of the family 

 of Desmidiese, nor was there any evidence in the gathering that they 

 might actually be zygospores of any form not yet known in the conju- 

 gated state. 



Hence, but for an observation made by me on a previous occasion, 

 the source of these curious bodies would have been not a little puz- 

 zling. 



