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like the one species from W. Australia that I have seen. 

 D. ignarus, Pasc. (from Sydney) is said to have elytral interstice? 

 much less distinctly punctured than those of D.Jossus, Newm.; 

 I have not seen any Deretaphrus (that comes near fitting the 

 description of ignarus) in which that character is apparent, nor 

 any at all from the Sydney region ; Mr. Lea has sent me a 

 Deretaphrus from Forest Reefs under the name ignarus, but as 

 its elytral interstices are quite as strongly punctulate as in fossus 

 I cannot think it rightly named. D. colydioides, Pasc. may 

 possibly be a Victorian species before me, but it is too vaojuely 

 described for confident identification. 



The most reliable and tangible characters for distinguishing the 

 species of Deretaphrus seem to me to be those of the pronotum, 

 and I divide the genus into three main groups founded on the 

 puncturation of that organ. In the first of these the punctures 

 are extremely fine and sparse (as in D. piceus, Germ). In the 

 second the punctures are still very sparse and decidedly fine, but 

 not nearly so fine as in piceus. In the third group they are 

 comparatively coarse and close (not much different from those of 

 D fossus, JSTewm.). Another valuable character is found in the 

 structure of the carina and stria which form the division between 

 the pronotum and prosternum. These do not, in any 

 Deretaphrus known to me, reach the front margin of the segment, 

 but cease at an interval from that margin which differs in 

 •different species ; in some species moreover, they end by becoming 

 :gradually feebler and when that is the case the front angles of 

 the segment (viewed from above) seem very obtuse or even non- 

 existent, while in other species they end abruptly and in that 

 case their terminus (viewed from above) has the appearance of 

 being a well-defined front angle of the segment from which the 

 •apparent apical margin projects forward (with a convex front 

 outline) towards the head. It is to be noted, however, that the 

 terminus of the lateral carina is in no species really at the true 

 front corner of the pronotum. In most of the existing descriptions 

 of Deretaphri a good deal of emphasis has been laid upon the 

 carination of the elytral interstices. So far as my observation 

 goes it is not a satisfactory character for exact definition. In 

 all species known to me of the genus the alternate interstices be- 

 come carinate (or more strongly carinate) near the apex and 

 undoubtedly the tendency of this carination to begin nearer to 

 (or even at) the base seems characteristic of species. Neverthe- 

 less, specimens of the same species (at any rate, specimens taken 

 in company and apparently of one species) seem to differ a little 

 inter se in this respec^, Moreover, in general the degree of con- 

 vexity of the interstices looks different from different points of 

 view. Among the considerable number of Deretaphri in my 



