Hood — On the Koftfera of the County Mayo. 665 



Ireland. It is indeed a happy hunting-ground, with its countless lakes, 

 its deep swamps of sphagnum, its endless bogs, and its fortunate im- 

 munity from drainage and reclamation. Though my short experience 

 has been confined to the west, I do not suppose for a moment that it 

 is any better than the centre or east of Ireland. As one travels be- 

 tween Dublin and "Westport, a distance of over 160 miles, as far as the 

 eye can reach one surveys a boundless tract of country unsurpassed 

 in its attractions for the naturalist. 



The following list enumerates about 220 species, of which a con- 

 siderable number are very rare. No species is here described as new, 

 and two only, Pterodina Mdentata and JEosphora elongata are recorded 

 for the first as new to Britain ; but two or three other species were 

 new, or new to Britain, when I first obtained them in the locality, 

 and in the case of several others I trust that I have elucidated points 

 previously obscure in their structure. 



My list is longer than that published about two years ago by Miss 

 Olascott, who catalogues 158 species (Proc. R. D. Soc. viii. (w.s.) 

 p. 29) chiefly from the eastern counties of Ireland. I regret that I 

 have not found any of the 24 new species described by Miss Glascott. 

 In regard to these new species, it must be said that Miss Glascott's 

 figures are somewhat lacking in detail, and this fault must lead to a 

 permanent difficulty in identifying the forms that she describes. In 

 many cases it seems probable that her species are not really new to 

 science. Professor D'Arcy Thompson (under whose guidance this 

 Paper has been prepared) suggests that the following forms are identi- 

 cal with the annexed older species : viz. — 



Notommata cylindriformis, Glascott, with Proales orthodon, Gosse. 



ProaUs inflata, Glascott, with Furcularia sphcerica, Gosse. 



Furcularia megalocephala, Glascott, with F. lactistes^ Gosse. 



Furcularia semisetifera, Glascott, with F. eva, Gosse. 



Rotifer phaleratus, Glascott, with R. vulgaris, var. 

 And further that there is at least a striking, if not a suspicious, resem- 

 blance between the following : — 



Notommata ruhra, Glascott, and N. torulosa, Duj. 

 Furcularia rigida, Glascott, and Proales coryneger, Gosse. 

 Eosphora striata, Glascott, and F. naias, Ehrenb. 

 Diglena inflata, Glascott, and Furcularia inflata, Gosse. 

 JD. elongata, Glascott, and F. silpha, Gosse. 

 B. dromius, Glascott, and F. uncinata, Milne. 



In yet other cases, Miss Glascott's identifications seem open to doubt ; 



