277 



Although the majority of the Australian species may be 

 readily referred to Blackburn's groups, a rather more natural 

 grouping would appear to be as follows: — 



1. Blackburn's Group 1 (several species have but one 

 of the two characters noted for this group) and the first pait of 

 Group 2 (except iirohoscideum). 



2. The second part of Group 2. 



3. One species — proboseideinn . 



4. Blackburn's Group 3. 



In his revision of the genus he had occasion to give 

 distinctive names to certain parts of the head. To make 

 these easily recognisable a figure of the head of truncatum 

 is given here. The names that he used are as follows: — 



A. Frontal elevation (a tubercle, 



horn, or ridge). 



B. Clypeal elevation (usually a 



carina). 

 CC. Frontal margins (also usually 

 a carina). 

 I). Frons (usually a more or less 

 depressed space). 



E. Clypeus. 1. Middle area. 



2. Lateral areae. 



F. Frontal wing (an enlarged 



CailtllUS). BoLliOCEEAS truncatum. 



Usually the parts named are readily traceable, but 

 specific and individual variations are numerous. On the 

 female of truncatum the crypeal elevation is frequently in the 

 form of an acute carina, but it gradually disappears till on 

 some specimens the clypeus and the frons are without a 

 dividing line or suture, although the lateral areae are marked 

 off by acute carinae. 



BOLBOCERAS PROBOSC1DEUM, Schreib. 



PL xxxiii., figs. 37 to 42. 



Bolboceros proTjoscidcum, Schreib. : Trans. Linn. Soc, 1802. 

 p. 189, pi. xx., fig. (male) 2; Westw. : I.e., 1848, p. 13, pi. iii,, 

 fig. (female), 1: W. S. Macleay : Hor. Ent., i., p. 122; Griff.: 

 Anim. Kingd. Ins., pi. xh, fig. (male) 4; Frogg. : Aust. Ins., pi. 

 xvii., fig. (male), 1. 



Austral asiae, Kirby : Trans. Linn. Soc, 1818, p. 462, pi. 

 xxiii., fig. (female) 5. 



var. Kirbyi, Westw. (nee Hope, nee Bainhridge) : I.e., 1848, 

 p. 13, pi. iii., fig. (male)- 2. 



var. terra e-reginae, Blackb. : ante, 1899, p. 25; Proc. Linn. 

 'Soc. N.S. Wales, 1904, p. 483. 



The wonderful variation in the structure of the clypeus of 



the male of this species is without parallel in the Australian 



