lo-i I'ALriCuKNIA — llYDROrillLlDAE. 



Chaetarfhria, 



Nearly gloljular. Black, shiny, sides rather lighter ; 

 under-side pit(3h-brown. Elytra with a furrow near suture 

 on hinder part. L. -^ — f 1. Common. 



C. seminulum, Payk. 



SI" EH CIIEIDES, 



Outer lobe of maxillae slender ; breast not ridged ; head 

 emarginate in front. Sperchcus, Kug. 



SpercJieKs. 



Oval, convex. Yellowish-brown ; disc of head and of 

 thorax darker ; elytra with scattered dark spots and a dark 

 longitudinal band near suture. L. 3 1. Very rare. 



S. emarginatus, Schall. 



HEL OPIIOmnES. 



A, Maxillary palpi nmch shorter than head and thorax. 



a. Last joint of maxillary palpi longer than the penul- 

 timate. 



I. Thorax distinctly broader than long, wider than 

 head with the eyes. 



Antennae nine-jointed ; abdominal segments Hat, the 

 first not ridged, last joint of posterior tarsi not so long as 

 all the rest together. HeAofliorus, Fab. 



JJ. Thorax about as long as, or longer than broad, 

 narrower than head with the eyes. 



Antennae seven-jointed ; first four al:)dominal segments 

 transversely raised, the first with a longitudinal ridge ; last 

 joint of posterior tarsi as long as all the rest together. 



Hyclrochus, Leach. 



b. Last joint of maxillary palpi shorter than the ])enul- 

 timate. 



Antennae nine-jointed ; last joint of maxillary palpi 

 shorter and more slender than the penultimate joint ; 

 labrum slightly sinuate in front ; eyes prominent ; pro- 

 sternum not ridged bet\\'een the anterior coxae ; abdominal 

 segments not raised transversely. Ochthebius, Leach. 



