BY ARTHUR M. LEA. 595 



of slightly diflferent width, and the intercoxal process of abdomen 

 wider than in 9- 



Other variations. — The rostral carinse are usually more distinct 

 in (^ than in ^j but sometimes vice versa; the central one of the 

 forehead is often entirely obsolete; it is usually sufficiently distinct 

 and occasionally sharply raised. The transverse impressions of 

 the prothorax are very seldom equal in depth, the posterior usually 

 being distinctly the shallowest, and it is sometimes entirely con- 

 cealed by scales. In an occasional specimen the eye appears 

 (carbo) to be almost perfectly circular, and more convex than is 

 usual; this is caused in part by a small ridge which is sometimes 

 beneath the lower extremity of the eye, and partly by the denu- 

 dation of scales; it is usually the case, however, that the eyes are 

 slightly more convex and smaller in J" than in 9- 



Before dealing in detail with Mr. Pascoe's table (Trans. Ent. 

 Soc. Lond. 1870. p. 16) I would here remark that tabulations 

 dependent upon the comparative proportions of parts (unless 

 such as there is no possibility of being in doubt about) 

 appear to me to be more likely to lead to confusion than to be of 

 practical value. In describing a new species of Catasm-cus the 

 Rev. T. Blackburn remarks* : — " I cannot say confidently where 

 this species would fall in Mr. Pascoe's taMe of Catasarci, for I 

 am unable to arrange the species of the genus in Mr. Pascoe's 

 groups, where a main distinction! consists in the species being (a) 

 moderately or (b) strongly ' convex above.' If this species is 

 regarded as ' moderately ' convex above it must be near ojnmus; 

 if ' strongly' it is probably near fiffloratus." 



Mr. Pascoe widely separates his supposed species on sexual 

 differences, and also on account of the scales, and as the scales in 

 most insects are exceedingly liable to abrasion I am of opinion 

 that they should scarcely even be used for this purpose. 



I now proceed to take the names seriatim : — 



Catasarcus spinipennis, Fahrs. (Mast. Cat. Sp. No. 4530). — 

 As this is the original description, Fahrteus's name must stand. 



tleport of the Horn Expedition to Central Australia, Part II., p. 289. 



t Section 1. 



