146 ON THE AUSTRALIAN CLIVIN1DE&, 



irregular depression of variable depth (frontal ■impressions); the 

 seta found on each side of the clypeus is situated in the frontal 

 impression, often the puncture from which it rises is lost in the 

 rugosity of the impression : from the frontal impressions the 

 facial sulci extend backwards on each side of the face, and in 

 some species (e.g., C. ohliquata, Putz.) a short light internal impres- 

 sion extends from the anterior part of the facial sulcus obliquely 

 inwards and backwards on each side of the face — the facial sulci 

 may then be said to be recurved (this is a feature of evident 

 classificatory importance). The clypeus is large, usually not 

 divided from the front between the frontal impressions; when it 

 is so divided it is by a wide usually irregular impression. It is 

 necessary for descriptive purposes to divide the clypeus into three 

 areas, viz. — (1) The clypeal elevation ("elevation anterieure " of 

 Putzeys) being the raised part of the clypeus between the frontal 

 impressions — (reference is usually made by me only to the shape 

 of the anterior margin of the clypeal elevation); (2) the median 

 part ("epistome" of Putzeys) being the central part of the clypeus 

 in front of the clypeal elevation (usually I refer to the anterior 

 margin only as the median part); (3) the winys ("petites ailes" 

 of Putzeys) being the lateral parts of the clypeus (usually a finely 

 marked suture is noticeable between the wings of the clypeus and 

 the supra-antennal plates). The form of the anterior margin of 

 the clypeus varies greatly, these variations being important for 

 grouping the species; among the Austi'alian species there are 

 three well marked forms of the anterior margin of the clypeus, of 

 one or other of which all different forms may be considered as 

 merel}'^ modifications; these are :— 



(a) The median part projecting on each side beyond the wings, 

 in which case it is angular, the lateral angles being more or less 

 marked (e.g., C. angustula, Putz.). 



(b) The median part in no way separated fi^om the wings along 

 the anterior margin (e.g., C. australasue, Bohem.). 



(c) The wings projecting strongly beyond the truncate median 

 part (e.g., C. procera, Putz.). 



