344 CATALOGUE OF THE ENTOZOA 



part of the invertebral kingdom which has not hitherto en- 

 joyed much of the attention of British Zoologists) which I 

 have met with in this country, the great majority of them 

 being new to the British fauna ; in order to render it so far a 

 perfect Ust of our indigenous species, I have included a few 

 which I have not been so fortimate as to find myself, but 

 which have been noticed or described by others, particularly 

 by Dr. Drummond, the President of the Belfast Natural-His- 

 tory Society, whose talents have already contributed to ad- 

 vance more than one branch of Natural History, and who 

 has lately turned his attention to these much neglected ani- 

 mals, and has described some species altogether new to 

 science. 



Under the general name Entozoa (derived from evtoj intus, 

 ?aov animal), are included all the animals which naturally and 

 permanently reside in the ahmentary canal, or some other 

 part of the interior of animals. And although the habitat 

 of any animal is not a sufficient ground to separate it from 

 the genera or species which approach it in organization, 

 yet as the Entozoa have been studied and described as a 

 separate group by those naturalists whose authority upon the 

 subject is the highest; and as the majority of them are dis- 

 tinct in organization from any animals not parasitic ; and as 

 we are as yet far from having arrived at a natural arrange- 

 ment of invertebral animals, (there being some groups which 

 though not parasitic, require to be associated with the Ento- 

 zoa, and others which are parasitic, and which many have 

 arranged with these animals, but of which the true situation 

 is extremely doubtftQ) : — it appeared to me to be more pru- 

 dent to retain the term in the sense used by Rudolphi and 

 Bremser ; and on the present occasion I shall confine my- 

 self altogether to the true Entozoa, or those species which in- 

 habit some part of the interior of the bodies of other ani- 

 mals; and I shall not enter at all upon the disputed point, 

 as to the place which these animals ought to occupy, in a 

 natural arrangement of the invertebral kingdom. 



The animals included under the term Entozoa, although 

 they have been very carefully studied by several continental 

 zoologists, and have occupied a considerable share of the 

 attention of several distinguished comparative anatomists, 

 have from some cause or other been little attended to, I might 

 almost say completely overlooked by British naturahsts, even 

 by men distinguished in other departments of the science. 

 " While there are some branches of Natural History (as Mr. 

 Jenyns has obseiTed in his report on Zoology) which are 

 most sedulously cultivated by us, there are others which have 



