Dr. O'Bryen Bellingham on Irish Enfozoa. 401 



Genus 21. Ccexurus. 

 (Derived from h:onus, communis, and ovpli, Cauda.) 



Gen. Char. — A simple vesicle filled with fluid common to a number 

 of individuals, to which they are adherent. Body soft, exti-emely 

 short, somewhat cylindrical, rugose rather than articulated. Head 

 distinct, provided with four discs and a short armed rostellura, si- 

 milar in almost every respect to that of the Cysticercus. 

 The digestive apparatus consists of four suctorial mouths, from 

 wliicli canals have been traced backwards towards tlie common 

 vesicle, but not continued into it. The genus was establislied by 

 Rudolphi for a species which is occasionally developed in the 

 brain of sheep and other Kuminantia. 



Ccenurus cerehralis * 1 R • ' f d p (O Is 



Polycephalus cerebralis (T. haennec) ... > '. .. x - V \ 

 Tccnia cerebralis (Pennant, Turton) .... J ■'' 



* The Ca^mtrus cerebralis consists of a vesicle of a larger or smaller 

 size common to many individuals ; the latter being disposed in groups 

 over its surface, and appearing to the naked eye merely as clusters 

 of opake white spots. The heads resemble those of the Cysticerci, 

 each being provided with an uncinated proboscis and four discs, 

 from which canals have been traced towards the common vesicle, but 

 not continued into it. 



The development of the Camurus cerebralis in the brain of sheep 

 gives rise to the disease known to shepherds under the name of stag- 

 gers, or bladder in the brain ; they are very seldom found in animals 

 above two years old, and they may be seated in the ventricles of the 

 brain, in its substance, or upon its surface ; in the two former cases 

 the disease is nearly incurable, in the latter the animal may be re- 

 lieved by an operation. The symptoms of course are owing to pres- 

 sure upon the brain, which will increase as the Ccenurus increases 

 in size, and -will vary according to the situation in which tlie en- 

 tozoon is developed, and to the amount of compression which it 

 occasions. 



In the early stage of the disease the animal appears to be stupid, 

 does not keep with the flock, staggers in moving, and hangs its head ; 

 the pupil is dilated, and becomes circular instead of oval. In the ad- 

 A'anced stage of the disease I have seen the animal with its head in- 

 clined to one side, and hanging so low that its nose almost touched 

 the ground ; at the same time it continued to turn round upon the 

 same spot for many hours ; it appeared to be blind, and would not 

 feed. 



When the Canurus cerebralis is developed upon the surface of the 

 brain, or near to it, the pressure causes absorption of the bone at 

 the part, the skull becomes thinned and soft at this place, and the 

 operation of perforating the bone and evacuating the contents of 

 the vesicle has been sometimes successfully performed. In general 



Ami. i^- Mag. N. Hist. Vul.xiv. 3E 



