British Species of 'H.-A\i])]\is. 110 



6. //. heydeni, Weluicke. 



My acquaintance with this species has, until this year, 

 been somewhat limited, and, until I took specimens in the 

 New Forest (Hants S.) and in Cambiidge, I had never 

 seen it in the field, although I had seen a few specimens from 

 the collections of various friends. It is apparently a pond- 

 species like H. rujicollis, but it is more localized in our islands. 

 I liave seen specimens from Lanes !S. and Chester, and there 

 is a Leicester record, but otherwise all records are for south 

 of a line drawn from the Wash to Hereford — Gloucester E., 

 Oxford, Berks, Middlesex, Surrey, Kent W., ? Sussex E,, 

 Hants S., L of Wight, l3orset, Devon N. and 8., Caznbs, 

 and Norfolk E. 



The species, in general appearance, is easily mistaken for 

 a small ruficol/is, but in the (^ the equal ant. tarsal claws 

 and the form of the aedeagus at once separate it. Apparently 

 the ? usually has the elytra without tine puncturation or 

 with only the apex thus marked, but there are many small 

 females which are completely punctate which may or may 

 not be this species. 



General Suininary of Characters. — 



f 1. General form: small, most likely to be mistaken for small 



I nificollis, but usually slightly wider in proportion to length. 



A.<( 2. Thorax much as in H. rvJicoUis, but with sides almost straight. 



] 3. Thoracic strife as in H. rujicollis. 



1^4. Elytra as in H. rujicollis. 



- I 1. Ant. tarsal claws equal and both finely built (cf. H. rujicollis). 



(2. Easal segment of median tarsus not excised on posterior side. 



( 1. Elj'tra perbaps normally with tine puncturation only at extreme 

 Q J apex at the most, but small specimens with tine punctura- 



^ ■ 1 tion all over elytra occur, which, on this character alone, must 



( be named H. rujicollis. 



The sedeagus is of a very distinct form with large hood 

 and moderate-sized saccular region. This last has a raised 

 ])art, ])resumably corresponding to the " wing" in nomax and 

 ruJicoUis, but it is more or less globular at the anterior 

 end of the region. The " tongue " is short and small and in 

 the figure is shown slightly out of its groove. The left 

 accessory lobe is in a way intermediate between the usual 

 type and that seen in the next species. 



7. H. immaculatusj Gerhardt. 



This is another species which is chiefly found in lakes and 

 canals. It is frequently associated with H. nomax, and its 

 range in our islands corresponds fairly well with that of this 

 species, covering, however, a larger area in the south. In 



