158 Browne: The Aquatic Coleoptera of the Isle of Man. 
The Manx list contains eleven species not found in the 
Lancashire list, and fourteen species absent from the Cum- 
berland list. If, however, we combine the Lancashire and 
Cumberland lists, giving a total of about one hundred and 
forty-four species, only seven species remain peculiar to the 
Isle of Man :— 
Bidessus minutissimus. Helophorus poyculus. 
Tlybius subeneus. Hydvena testacea. 
Gyrinus uvinator. Octhebius lejolisit. 
Paracymus nigroeneus. ue 
Compared with the ‘Solway’ list which has about one 
hundred and twenty species there are nine species which are 
peculiar to the Isle of Man :— 
Noterus sparsus. | Cymbiodyta ovalis. 
Deronectes latus. | Paracymus nigroeneus. 
Ilybius subeneus. Berosus affinis. 
Gyrinus urinator. | Helophorus affinis. 
MaVINUS. ‘ 
As against the combined lists of Antrim and Down, containing 
about one hundred and seven species, the Manx list has thirteen 
peculiar species :— 
Bidessus minutissimus. | Helochares punctatus. 
Devonectes latus. Laccobius ytenensis. 
Agabus biguttatus. Bevosus affinis. 
Ilybius subeneus. Hydvochus angustatus. 
Copelatus agilis. Hydrena testacea. 
Cymbiodyta ovalts. - atricapilla. 
Pavacymus nigvoenens. 
From these three lists there is a slight indication that the 
Manx water beetles are more like those of North-West England 
than those of either South-West Scotland or North-East Ireland 
but an analysis of the lists will bring out this fact much more 
clearly. i: 
First of all with regard to Ilybius subeneus, which appears 
in all three lists, we might probably regard the specimen as a 
stray one, and the record as belonging to the ‘ ectopic’ ones 
to which I referred in a previous paper,* and we can therefore 
neglect it in discussing the lists. With regard to the list of 
species peculiar to the Isle of Man as compared with the north- 
west of England, five of the species are found both north and 
south of that district, so that their absence from that list is 
probably only a temporary one. One species only, therefore, 
is of importance as indicating a difference between the faunas 
of these two districts, 7.e., G. urinator, a southern species, 
present in the Isle of Man, and not found in the north-west of 
England. I have already pointed out that there are records 
for Yorks. N.E., and Durham, but that these are beyond the 
normal British range of the species. 
” 
* Aquatic Coleoptera of the Mid-Ebudes, ‘ Ann. Scott. Nat. Hist.’, 
April, 1910. 
Naturalist, 
