88 REVISION OP SYMPETES AND HELiEUS, ETC., 



d. Size large / tricostelhis 'White. 



\ Madeayi Pasc. 



dd. Size smaller, punctures much finer rotundatus Breme. 



aa. Explanate margins of elytra together not as wide as disc at base. 



e. Elytra about as wide as long orbicularis Breme, 



ee. Elytra much wider than long. 



/. Anterior angles of prothorax obtuse excisifrons, n.sp. 



jf. Anterior angles subdentate and rectangular. 



quadratus, n.sp. 



C Explanate margins of elytra undulating \ testudiiieios Hope. 



1 undulatus Lea. 

 D. Explanate margins of elytra narrow, size small. 



a. Elytral suture carinate. 



h. Prothorax carinate , unicarinatus Boisd. 



bb. Prothorax not carinate. 



c. Anterior angles acute and salient subriigosus Breme. 



cc. Anterior angles not acute and salient patelliformlsFeLSc. 



aa. Elytral suture not carinate j Bremei Hope. 



{ Duboidaii Pasc. 



H E L iE u s Latreille. 



This genus has been discussed by de Breme in 1842, and again 

 by Macleay in 1887. The Rev. T. Blackburn, in 1899, added 

 .several new species and gave an excellent table for identifying 

 the larger species (Trans, Roy. Soc. South Aust. 1899, p. 37). 

 The acquisition of new material, and a study of this group enable 

 me to add a few notes, and tables which may help students to 

 identify the known species with greater facility. Reasons have 

 already been given why little regard should be paid to the varied 

 overlapping of the anterior prothoracic processes (These Proceed- 

 ings, 1909, p. 124). Nor is colour a i-eliable test of difference of 

 species, since immaturity is often the cause of such difference. 



The groups fall naturally into five sections. 



Section i. — Those liaving elj^tra smooth or only granulate. 

 Section ii. — Those having elytra pilose or tufted. 

 Section iii. — Those having elytra bicostate (or with the suture, 

 tvbcostate). 



Section iv. — Those having elytra 4- or more costate. 

 Section V. — Tho.se having elytra tuberculate. 



