COLYMBETES. 115 



h. First three joints of male anterior tarsi considerably 

 dilated, laterally not compressed. 



I, Thorax yellow, with a large transverse spot in 

 middle and usually two side spots, and the middle 

 of posterior margin black. 



Oblong oval, moderately convex. Head yellow, vertex 

 and forehead black ; under-side black, prosternum yellow, 

 al)dominal segments bordered with yellow in male, almost 

 entirely yeUow in female ; legs yellow. L. 5 1. Common. 



C. notatus, Berg. 



II» Thorax yellow, with middle of anterior and pos- 

 terior margins black. 



Oblong ovate. Head yellow, vertex and two frontal spots 

 black ; under-side black, part of prosternum reddish or 

 yellowish, legs yellow. L. 5 1. Moderately common. 



C. bistriatus, Berg. 



m» Thorax pale brownish- yellow, middle of posterior 

 margin sometimes rather darker. 



1. Under-side reddish-yellow. 



Oblong oval. Head reddish-yellow, vertex and two 

 frontal spots black. L. 5 1. Common. C. cxoUUls, Forst. 



A?. Breast and abdomen black, middle of former, 

 margins of segments of latter yellow. 



Oval. Head pale brownish-yellow, spotted with black 

 at base. L. 4| 1. Rare. C. ahcrratus, Har. 



IlyhUis, 



A, Posterior coxae much extended' in front, their anterior 

 margin forming an almost angular projection, the side 

 pieces of metasternum consequently narrow and curved 

 backward. 



Oval, broadest rather behind middle. Upper-side bright 

 bronze, side margin of thorax and elytra and the whole 

 under-side and legs red-brown. L. 5 1. Kather common. 



/. fcncstrahis, Fab. 



H. Posterior coxae with a curved anterior margin, side 

 pieces of metasternum rather Ijroad and almost triangular. 



I 2 



