Dr. O'Bryen Bellingham on Irish Entozoa. 471 



ten cells, which are placed alternately opposite to the concave 

 faces of the inner cells and the junction of their sides ; in the 

 former case they have three, and in the latter four faces besides 

 the external margin. 



When there is a third circle it generally consists of fifteen 

 cells. In all the varieties the cells of the external circle are 

 notched, and their segments more or less prolonged ; but the 

 length and form of the rays are very variable. 



Meneghini describes several diaphanous vesicles in each cell. 



Sometimes plants are met with having more than three circles ; 

 these are probably the Micrasterias elliptica, Ehr. Infus. p. 158. 

 tab. 11. fig. 9, which Meneghini refers to the present species. I 

 am not however satisfied that it is not distinct ; the external cells 

 agree with the description given above, but the inner ones are va- 

 riable in number and not arranged in regular circles. Whether 

 it possesses any other distinctive character I have not yet clearly 

 ascertained. This form is fig. 21 of the f American Bacillaria/ 



Plate XII. fig. 7. P. Boryanum : a, central cell ; b, a cell of the inner 

 circle ; c, marginal cells. 



Plate XII. fig. 8. P. Boryanum, var. : a, central cell ; b, marginal cells. 



LVI. — Catalogue of Irish Entozoa, with observations. By O'Bryen 

 Bellingham, M.D., Fellow of and Professor of Botany to 

 the Royal College of Surgeons in Ireland, Member of the 

 Royal Zoological, Geological and Natural History Societies of 

 Dublin, &c*. 

 One of the objects contemplated by the Natural History Society 

 of Dublin on its formation, was to obtain, at as early a period as 

 circumstances permitted, a complete catalogue of the animals, 

 vertebral as well as invertebral, which are natives of this country. 

 With the wish to contribute as far as lies in my power to so 

 desirable an object, I have brought forward the following cata- 

 logue of Entozoa, or parasitic animals (a part of the invertebral 

 kingdom which has not hitherto enjoyed 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 list of our indigenous species, I have 

 included a few which I have not been so fortunate as to find my- 

 self, but which have been noticed or described by others, parti- 

 cularly by Dr. Drummond, the President of the Belfast Natural 

 History Society, whose talents have already contributed to ad- 



* In order to complete Dr. Bellingham 's Catalogue of Irish Entozoa, 

 and to include all the species known in our volume for the current year, we 

 have reprinted the first portion (containing the genera Filaria, Trichosoma, 

 Trichocephalus, Oxyuris, and Cuculanus y ) which was originally published, in 

 Charlesworth's Magazine of Natural History. — Ed. 



