Coelamhus.'] Adephaga. IHT 



broadest part of tlie body ; the sixth abdoininal segment is much longer than the fifth, 

 and with the seventh uiid cightli becomes much narrower beliiiid, the hist tapering oti" 

 into ;in abrupt bhiiit point; tlie cerci are long, and l)car long setaj at base and apex; 

 the legs are slender and rather long, and end in equal claws; the colour is pale with 

 the head and scuta luteous, with a few small dark spots ou head and segments: the 

 pupa is short and broad, and is chietly remarkable for being covered with thick and 

 strong setffi. 



The description of tliis larva will serve for that of a DeronedeA or a 

 typical Ilydroporus : the larvae of D. d('X>resi<us, II. halensis, and //. 

 palustris dilier very slightly from it, the dilferences being chielly found 

 in colour, pubescence, length of cerci, and one or two other points. 



I. Labrum much concealed, head rounded 

 in front, front with a more or less dis- 

 tinct raised margin; form very short and 



convex, 

 i . Head with two strong broad impressions, 

 leaving a ridge in centre ; length 3 mm. 



1. Punctuation of elytra double, con* 

 sisting of large and small punc- 

 tures. 



A. Larger punctures more scattered C. \EU^lcOt.on,Schnll . (reliculalus, i\). 



B. Larger punctures closer together C. QUINQUELINKATUS, Zett. 



2. Punctuation of elytra uniform, deep 



and strong C. iNiEQUALis, i''. 



ii. Head with at most a narrow impression 



near eye; length 2 mm C. DECOKATrs, G^y^^. 



II. Labrum little concealed or ([uite con- 

 spicuous ; head emarginate in middle of 



Iront, front not margined, 

 i. Short oval ; elytra with apical angle 



plainly produced into a short sharp point C. CONFLUE.vs, F. 

 ii. Long oval; elytra with apical angle not 



produced. 



1. Thorax with a dark si)ot on disc. 



A. Punctuation very line ; thorax 

 uniformly punctured ; none of the 

 dark markings reaching base of 



elytra C. novemlineatu?, Slejih. 



B. Punctuation coarser ; thorax im- 

 puQctate ou centre of disc ; some 

 of the dark markings always 



reaching base of elytra. . , , C. PAEALLELOQRAMMUS, .4//>\ 



2. Thorax without dark spot on disc; 



punctuation very coarse , C. IMPEE3S0PDNCTATIJS, Suhall. {pieipes, F.). 



In some of the members of this genus the females are very markedly 

 dinior})hic, i.e. present two dillerent forms, in the one case being shiny 

 like the male, in the other dull and ojjaque ; this is to a greater or less 

 extent a characteristic of the whole of the Dytisci complirati, and will 

 be again referred to un(h'r the genus Di/tisciis, in whicli the feiiudcs 

 attain the greatest amnuiit of sexual diiference frt'iii the males. 



C> versicolor, Schall. {refiruia/tio, F.). Short oval, convex, rather 

 sliiiiy, siiiiM.ih ; l\ead and thorax thickly and tiucly punctured, fcnu- 

 ginous ; elytra at base broader than base of thwrax, very tiiickly and 



