1918.] V. H. Gravely : Passalidae of the World. 19 



Aulacocyclus deyrollei, Kaup. 



Aulacocyclus deyrollei, Kaup, 1868a, pp. 7-8. 

 Taeniocerus deyrollei, Kuwert. 1897, p. 275. 



One specimen 25 5 mm. long, in the Indian Museum collection. I have also examined 

 specimens in the British Museum. 



A. deyrollei differs from A. master si only in the much greater breadth of the central 

 tubercle and in the more conspicuous puncturing of the anterior part of the head. 



Aulacocyclus tricuspis, Kaup. 

 Fig. Ill, 5. 



Aulacocyclus tricuspis, Kaup, l868a, p. 7. 



Several specimens from New Caledonia and one from Woodlark Island. Length 22-2- 

 mm. 



This species is easily recognised by the tridentate form of the central tubercle which 

 resembles that of Comapcupes cavicornis, except that it is always broadest between the 

 paired dorsal denticles. The antennal lamellae are much shorter than in A. deyrollei. The 

 punctures in the grooves of the elytra are almost uniformly coarse. 



Aulacocyclus errans, Blackburn. 

 Fig. Ill, Ô. 

 Aidacocydus collaris, Blackburn, 1896, p. 233. 



Both sexes of this species appear to occur in two forms distinguishable from each other 

 only by their size. 



Large form. — -Several specimens from Queensland. Mr. H. Schroder has presented us 

 with specimens from the New England District of New South Wales. Length 27-30 mm. 



Small form. — Numerous specimens from Queensland, including four from Cooktown. 

 three from the Mclvor Kiver and one from Cardwell. Length 19-6-23-0 mm. 



The antennal lamellae are somewhat shorter than in A. deyrollei. The central tubercle 

 rises almost vertically and is then bent over forwards, the antero-ventral surface gradually 

 and the postero-dorsal abruptly, the dorsal surface being straight and more or less 

 horizontal. The anterior enlargements of the pronotal marginal grooves are somewhat 

 more pronounced than in other species of the genus. The grooves of the elytra are 

 even more coarsely punctured than in A. tricuspis. 



Aulacocyclus edentulus (MacLeay). 

 Fig. Ill, 7. 

 Passalus edentulus, MacLeay, 1826, p. 439. 

 A number of specimens from Queensland (Brisbane), New South Wales (Sidney) and 

 Victoria. Length 23-30 mm. 



The central tubercle is more strongly elevated than m A . errans and less abruptly bent 

 forwards. The anterior enlargements of the pronotal marginal groove are not very 

 pronounced. The elytral grooves are less strongly punctured, especially dorsally. 



Aulacocyclus teres (Percheron). 

 Fig. Ill, 8. 

 Passalus teres, Percheron, 1841, pp. 39-40. 

 A number of specimens from Queensland, New South Wales and Victoria (Melbourne). 

 Length 30-8-40-0 mm. 



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