55 



means exact. I find, However, that more satisfactory results 

 are arrived at in respect of the species I have studied by an 

 examination of the setiferous teeth on the " inferior ridge." 



I will now proceed by way of illustration to mention the 

 characters of the external and inferior ridges in several species 

 of Oarenum, remarking, however, that C. antJiracinum, Macl., 

 and C. Icevigatum, Macl., are the only species of which I have 

 been able to examine a long series. 



C. ajithracimcm, Macl. — Exterior ridge with four teeth, all 

 feeble — the topmost extremely so ; all invisible when the tibia 

 is looked down upon quite perpendicularly. Inferior ridge 

 bearing six or seven well-defined teeth, which commence far 

 back from the tarsus. 



C. IcBvigatum, Macl. — Exterior ridge with four very well- 

 defined teeth, the lowest two of which are more or less visible 

 when the tibia is looked down upon perpendicularly. Inferior 

 ridge with ten well-defined teeth, which commence far back 

 from the tarsus. 



C. Oclewahni, Cast. — ^Exterior ridge with only three distinct 

 teeth, of which the lowest is a little visible when the tibia is 

 looked down upon perpendicularly ; a fourth is barely discover- 

 able, but is indicated by the presence of its seta. Inferior 

 ridge with twelve teeth, which commence close to the tarsus. 



C. ineditum, Macl. — Exterior ridge very similar to that of C. 

 anthracinum. Inferior ridge with nine teeth, which commence 

 far back from the tarsus, the topmost barely traceable except 

 by its seta. 



These examples will be quite sufficient to illustrate what I 

 conceive to be the advantage of giving more attention than 

 has been given hitherto to an accurate study of the anterior 

 tibia in Carenum, and I have not access, unfortunately, to so 

 large a series of species as would render an exhaustive and 

 complete study of the genus possible for me. 



Before leaving the subject I will jusfc add a few notes on the 

 application of the characters of the anterior tibia to the dis- 

 tinction of the Australian genera of ScaritidcB. 



Monocentrum is a genus of which I have no example, but 

 probably its tibial structure is peculiar. 



In Oonopterum (two species only have been examined) the 

 exterior ridge seems to contain two teeth and an obsolete indi- 

 cation of a third, while the inferior ridge commences as in 

 Carenum, but contains only about three teeth, and is non- 

 serrate in its upper half. 



In Garenidmm I have been able to examine only a single 

 species, but it has the exterior ridge very ill-defined, and quite 

 devoid of teeth above the apical large teeth, and six blunt 

 obscure teeth on the inferior ridge. 



