486 REVISION OF THE AUSTRALIAN SPECIES OF BOLBOCERAS, 



^'lateral" "areas of the clypeus") I shall call the "clypeus." On 

 either side of the frons a flattened or concave process projects 

 over (and cutting into) the e3^e, which I shall call the "frontal 

 wing," and in some species a carina runs forward from the back 

 of the head close to the eye (in other species that carina is 

 wanting, or confused with the frontal margin) which I shall call 

 the " margin of the head." One of the modifications of the 

 above characters seems to call for special remark, viz., that of 

 the parts that I have called the "clypeal arese." In the group 

 of species with multicarinate hind tibiae the lateral arese (so- 

 called) are in reality above and behind the middle area (sloping 

 backward towards the eye in the females; scarcely traceable in 

 the males — I think they form the lateral base of the frontal 

 horn). To a casual glance they appear to be behind the clypeal 

 elevation and therefore not part of what I have called the clypeus; 

 but' if these species be compared with those of other groups it 

 will be seen that the carina most nearly continuing the line of 

 the truncate middle part of the clypeal elevation does not really 

 correspond with the carina that (where it is not obsolete) in the 

 other groups is evidently the lateral part of the clypeal elevation, 

 but with the carina that in those species runs obliquely forward 

 and is unmistakably on the front face of (and a part of) what T 

 have called the clj^peus, and that the real continuation of the 

 clypeal elevation is the hinder of the two carinse that meet at 

 -each extremity of the truncate middle part of the cl3"peal eleva- 

 tion. As alread}^ remarked, this carina is scarcely (or not) trace- 

 able in the males of the First Group, but is lost in the base of 

 the frontal horn which throws out of form and includes in itself 

 all the other elevations of the front part of the head except the 

 clypeal elevation. The correspondence indicated above of these 

 carinae in different Bolbocerata will be most readily observed by 

 comparing a female of the First Group with a specimen apper- 

 taining to the Third Group, inasmuch as the carinee in question 

 take very variable directions in the Second Group, and in most 

 of its species can be identified only when the eye has been 

 trained by previous examination of the corresponding arese in 

 species of the Third Group and females of the First Group. 



