126 PALPICORXIA — HYDROPHILIDAE. 



Slightly convex. Upper-side l)liie-black, gTcenish-bronze 

 at sides. Punctures on elytra finer toward suture. lireast 

 sometimes reddish. L. 3 1. Kare. G. colymhus, Er, 



h, Reflexed margin of thorax and elytra brassy-black. 



I. Punctures on elytra scarcely finer toward suture. 



Oval, greatest breadth rather behind middle ; flatly 

 arched. Upper-side ])luish-black-gTay, suture and sides of 

 elytra brassy. Interstices of elytra finely punctured in 

 female, very indistinctly so in male. L. 3 1. Common. 



G. marinus, Gyll. 



II» Punctures on elytra much finer toward suture. 



Oval, greatest breadth in middle, flatly arched. Coloured 

 like G. marinus. Interstices of elytra finely punctured in 

 female. L. 2\ 1. Common. G. opacus, Sahib. 



OreetocJuJus. 



Oblong oval, convex ; dark brown, wdth slight bronze 

 lustre, finely punctured all over, with tolerably thick gray 

 pubescence ; under-side rust-red. L. 3 1. Pather common. 



0. villosus, Miill. 



PALPICOHNIA. 



A. First joint of posterior tarsi short. Hydrophilidae. 

 J>. First joint of posterior tarsi long. Sj)hacridiidae. 



Jlinn OPIIILIIJAE. 



A. Thorax narrower at apex than at base. 



a. First joint of posterior tarsi very short, second joint 

 long. 



Lal^rum not liidden ; femora compressed; antennae with 

 eight or nine joints. Hydrophilides. 



h. First four joints of posterior tarsi all equally short. 

 Labrum hidden ; femora almost cylindrical ; antennae 

 witli six joints, Sj^crchcidcs, 



