16S1.J . (J 



the Agabi, though rare in most localities, is the commonest insect in the Bog, and, 

 at certain periods of the year, may be taken by hundreds. A. unguicularis, Th., 

 very common. 



Dytiscus marginal is, L., not uncommon. D. circumcinctus, Ahr., rare ; a few 

 specimens have been taken. 



Hydaticus transversalis, Berg : several specimens have been taken on one side 

 of a small pond in Chandler's Whin, but it has occurred in no other part of the Bog. 



PHILHYDKLDA. 



Hydrobius fuscipes, L. : this ubiquitous insect is as abundant as it seems to be 

 everywhere else. 



Helochares lividus, Forst., not common. 



Philhydrus testaceus, F., very plentiful. Ph. nigricans, Zett., not uncommon. 

 Ph. ovalis, Th., not common. Ph. suturalis, Sharp : this seems very abundant ; it 

 appears to be this species, and not marginellus, F., as the yellow spots on the clypeus 

 are well defined in all the specimens I have examined. 



Anaccena variabilis, Sharp, very common. 



Laccobius minidus, L., very common. 



Limnobius truncatellns, Thunb., not uncommon. L. picinus, Marsh. : this beetle, 

 the smallest of the Philhydrida, is exceedingly abundant ; I have also found it near 

 Stamford Bridge, a few miles from York, but have never come across it elsewhere. 



Chcetarthria semimdum, Pk., common. 



Helophorus aquaticus, L., granularis, L., and grisens, Hbst., all very common. 

 II. aineipennis, Th. : I know of only one specimen of this insect having been taken 

 in the Bog. 



Ochthebius pygmreas, F., common. 



Hydrochus elongatus, Schall., not common. 



Hydrcena riparia, Kug., common. H. palustris, Er., not uncommon ; this is 

 one of the specialties of the Bog. 



Cyclonotum orbiculare, F., common. 



Besides water beetles, several exceedingly good species are taken 

 in Askham Eog : the best of these is the very distinct and very rare 

 Pselaphus dresdensis, Hbst., of which about a specimen a year is found ; 

 Oymnusa brevicollis also occurs ; Oodes helopioides is not uncommon ; 

 and Blethisa niultipunctata has been once taken under rubbish. The 

 Bog has not been worked systematically for the semi-aquatic insects ; 

 but Bagous petrosus, Tanysphyrus lemnce, and JPhytobius comari are 

 found, and probably many other species 'might be. Donacia lemnce is 

 at times abundant, but only in one particular pond, and other species 

 are perpetually turning up. 



1 may add that the Bog is now closed to the public, but leave to 

 work it can be obtained through Archdeacon Hey, in whose company 

 I have, within the past year, taken the greater number of the species 

 above mentioned, and who is as enthusiastic a collector now as he was 

 in the old days of Curtis and Stephens. 



Lincoln : May llth, 1881. 



