1901.] 91 



SOME REMARKS ON THE BRITISH SPECIES OF LIMNIUS. 

 BY G. C. CHAMPION, F.Z.S. 



My friend Mr. J. Edwards bas recently sent me for examination 

 four Limnii, from Norfolk, apparently belonging to as many species, 

 of which he enclosed enlarged photographs, taken by himself. If 

 these specimens are to be referred to two species only, as seems pro- 

 bable, there must be considerable variation in the sculpture, &c., of 

 the members of this genus, and it is therefore worth while calling 

 attention to them. The chief diflerential characters noticed by Mr. 

 Edwards between these four insects, which for convenience are here 

 referred to under the numbers 1—4, are as follows: — 



1. Elytra coarsely punctate-striate on the disc (the interstices ap- 



pearing convex), about 2\ times longer than the thorax ; 

 thorax shining on the disc. 



2. Elytra sculptured as in No. 1, about 2| times longer than the 



thorax ; thorax dull and rugulose on the disc. 



3. Elytra finely and somewhat shallowly punctate-striate on the disc, 



the interstices flat, each with a distinct single series of 

 punctures. 



4. Elytra as in No. 3, but without a distinct single series of punctures 



on each interstice. 



No. 1 is the common species known under the name of L. Darge- 

 lasi, Latr. (== tuberculafus, Miill., Jacnstris, Steph., variabilis; Steph., 

 etc.). No. 2 was found by Mr. Edwards at Honing, Norfolk, on July 

 10th, 1890, when collecting in my company. There is a specimen 

 very like it in Dr. Power's collection, and another in thatof Stephens. 

 Compared with X. Dargelasi the rugulose and relatively longer thorax 

 give the insect a somewhat different facies. Nos. 3 and 4 are, no 

 doubt, forms of L. troglodytes, Gr}'ll- (= Huviatilis, Steph.), and they 

 can be matched in a series of that species from Slapton in my collec- 

 tion. The single interstitial series of punctures shows very clearly 

 in Mr. Edwards' photograph of No. 3. His specimen of the latter 

 was taken near Norwich in April, 1882, and Stephens' L. fluvintilis is 

 also stated to be from Noi'folk. I have taken L. troglodytes in the 

 New Forest with L. Dargelasi, and at Soham, Cambs., and have seen 

 examples of it, from Horsell, mixed with the series of L. rivularis 

 in the Power collection at the British Museum. 



L. rivularis, Kosenh., is considerably smaller than any of the 

 above mentioned forms ; this insect has also been found by Dr. Power 

 in my own neighbourhood, but 1 have not yet met with it in the 



