208 Proceedings of the Royal Society oj Victoria. 



sculpture of the head or the number of joints in the antennal 

 flabelhim, no information in fact on Avhich it could be assigned 

 definitely to any of the genera I'ecognised in Masters' Catalogue. 

 The only two characters mentioned by Boisduval that enable it 

 to be said of any Australian Passalid that it is not Lottini are 

 the presence of a median impressed line on the prothorax (there 

 are very few Australian species which have not at any rate a 

 faint median line), and that indicated by calling the striae of the 

 elytra " leeves." I know of no Australian Passalid in which all 

 the elytral striae are impunctulate, but pi'obably Boisduval's 

 expression refers only to the dorsal strise (which are impunctulate 

 or nearly so in many species), and this view of the matter is 

 strengthened by the fact that the only other Australian Passa- 

 lides described by Boisduval have their dorsal elytral striae more 

 or less punctulate. Burmeister increases the difficulty by saying 

 that there is an example of Lottini in Dupont's collection, giving 

 the size as 24 1., and then proceeding to imply thiat he had not 

 seen Lottini by conjecturing that its antennal flabellum is likely 

 to be 6-jointed, because it is 6-jointed in the species that follows 

 Lottini in Boisduval's descriptions. The only other author that 

 I can find referring to Lottini is Kaup, who in a note on 

 Plesthenus quadricornis, says that the latter insect is named 

 Lottini, Boisd. in Mniszech's collection, and that it is impossible 

 to express an opinion as to whether it is or is not correctly so 

 named. Under these circumstances the only course practicable 

 is to treat the name Lottini as though it were non-existent, until 

 some further information is forthcoming. There have been a 

 considerable number of synonyms bestowed on the species of 

 Mastochilus, most of which are duly recorded in Master's Cata- 

 logue, but one very obvious case of synonymy seems to have 

 escaped notice hitherto, viz., M. impressicollis, Boheui. =poly- 

 phylliis, W. S. Macl., the latter being much the older name. 

 Thus there are at present 6 names (and 6 only), that it seems 

 practicable to regard as representing valid species of Mastochilus, 

 and I propose in the following pages to re-describe one of them, 

 and to add the description of a new one. 



The following table shows the distinctive characters of the 

 species known to me : — 



