INDIGENOUS TO IRELAND. 345 



for a long time lain comparatively neglected." This remark 

 is peculiarly appropriate, and applies particularly to the ani- 

 mals which form the subject of the present communication ; 

 they are commonly looked upon with disgust instead of any-, 

 thing of interest in a scientific point of view, and the num- 

 ber of individuals who have made them a study is exceed- 

 ingly hmited. Indeed, the Httle attention which the Entozoa 

 have attracted in these countries will be apparent from the 

 fact, that in the only works which contain lists of the Bri- 

 tish species, viz. * Pennant's Zoology ' and Turton's ' British 

 Fauna,' but twenty-eight species are described as indigenous ; 

 and four of these are repeated twice under different names, 

 leaving but twenty-four distinct species : while in the hmited 

 opportunities which I have had, I have detected and pre- 

 served upwards of 200 species, and several of these occurred 

 in six, others in ten, and one species in as many as fifteen 

 different animals. 



The Entozoa, although they do not form a very numerous 

 division of the animal kingdom, are very extensively distri- 

 buted, as in almost all the Mammalia, birds, reptiles, and 

 fish, which I have examined, I have detected some species, 

 and often more than one ; and there is scarcely a tissue or 

 organ in which they do not sometimes occur. 



I have found them in the oesophagus, stomach, and intes- 

 tines, in the bronchial tubes, and air cells of the lungs of 

 some animals ; in the urinary bladder, in the gall and swim 

 bladder of others ; in cellular tissue and in serous membranes ; 

 in the substance of the heart, in the liver and kidney ; some 

 species inhabit the brain of animals, others their eyes, others 

 aneurismal swellings of arteries, others the meatus audito- 

 rius, the frontal and maxillary sinuses, and even the cavity 

 of the tympanum. In fact there is hardly an organ in which 

 some species has not been detected, at least among vertebral 

 animals ; and if they are more rare among the Invertehrata, 

 it is, perhaps, because we have not yet sufficiently sought for 

 them. 



The number of animals which I have dissected in order to 

 complete this list, is very considerable : I possess notes of 

 having examined upwards of 270 Mammalia, 360 birds, and 

 380 fish, exclusive of reptiles which are indigenous to this 

 country. And here I have much pleasure in acknowledging 

 the assistance which I have received from Mr. Richard Glen- 

 non, preserver of animals to the Natural-History Society; 

 who most obhgingly placed at my disposal the body of any 

 animal sent to him to be preserved, which I was desirous of 

 examining ; indeed, without his kind co-operation, I could 

 not have brought this list to its present extent. 



