BY T. G. SLOANE. 405 



not, is a very important character. It does not vary in position 

 to the extent of being on the border in the great natural eques- 

 and opacicollis-groups; nor to the extent of being off the border 

 in the kinyi-, lateralis-, and lesueuri-gvoups. The violaceous- and 

 sphodi'oides-growps, as here constituted, can only be differentiated 

 in every case by this feature; and, though no doubt it cannot be 

 affirmed that the difference in the position of this pore is of great 

 importance between such species as N. opulentus and N. besti, 

 still, this seems a case where, there being a difference, it must be 

 used, on account of the great help it gives in arranging these 

 species. 



Striation of elytra. — A character of doubtful taxonomic value, 

 though, outside the chalybeus-group, only JV r . tenuistriatus and N. 

 apicalis have the disc faintly striate; in both these species, the 

 eighth interstice, at least, becomes convex near apex, which it 

 does not in the chat ybeus-gr oup. iV. sphodroides is the only 

 species, not belonging to the chalybeus-gvoup, in which all the 

 interstices, including the eighth, are depressed at apex. 



Width of eighth interstice. — Though the relative width of the 

 eighth and ninth interstices of the elytra does not vary in any 

 species, it is not a feature of group-value. 



Tenth interstice.— The, presence of a tenth interstice on the 

 sides of the elytra, near the apical sinuosity, is an ancient char- 

 acter; it seems to have originated outside the ninth interstice, 

 and not to be derived from the ninth interstice. It is found 

 also in other genera besides Notonomus. It varies greatly in 

 length and development in Notonomus, and has probably pro- 

 gressed towards greater expansion in some species (e.g., N. kingi), 

 while in others it has retrograded till it has become almost or 

 quite obsolete (e.g., J\ T . muelleri and JV. angustibasis) . 



Based border of elytra. —In my Table of 1902, too much import- 

 ance was attached to whether the humeral angle of the elytra 

 was dentate or not, for, although the form of the basal border at 

 its point of junction with the lateral border hardly varies at all 

 in any species (unless sometimes slightly in a variety), yet it is 

 impossible to define two different forms of the border at the 

 humeral angle, as I attempted to do in 1902; there is every 



