164 Rev. F. D. Morice on the 6th $ ventral segment 



T-shaped (niorawitzi), most of the " processes " I have 

 figured seem to group themselves. And it will be found 

 that with each type of process a corresponding type of 

 main lobes is associated — the apical margins of the latter 

 running somewhat parallel to the lobes of the process, 

 so that with a " Y-shaped process " they converge very 

 obliquely or diagonally, embracing a great triangular gap 

 in which lies the process ; while with a " T-shaped pro- 

 cess " they run nearly or quite transversely, there is no 

 deep triangular gap, but the process stands out clearly 

 and boldly beyond the lobes. Also in the latter case 

 the lobes have sharp lateral corners, generally armed with 

 an actual spine or tooth, though occasionally this is too 

 much deflexed to be conspicuous in the ventral view of 

 the segment. In segments of the c&mentaria type, on the 

 contrary, the lobes are untoothed, their apices are rounded 

 or subtruncate. (In such a case as Fig. 15 the process is 

 no doubt somewhat Y-shaped, but I should class the 

 segment as a whole under the other type, that otmorawitzi, 

 because the petiole of the process is wider than it ever is 

 in the cmmentaria type, the lobes of the process are, after 

 all, more transversely divergent, the apical margins also of 

 the main lobes running on the whole rather transversely 

 than diagonally, and terminating in an acute angle armed 

 with a distinct though deflexed tooth.) 



In the longitudinal sulcus, or narrow slit which separates 

 the two main lobes, another tooth-like object usually shows 

 itself, which, however, seems to be really only a pencil of 

 excessively stout and spine-like hairs. This, in segments 

 of the a&mentaria type, seems to be generally ill-developed 

 or even absent. 



The pilosity of the main lobes may differ greatly even 

 in closely related species (cf. Figs. 11 and 13). As to the 

 process, its apical lobes are generally densely clothed 

 externally with excessively fine hairs, varying in length 

 and direction according to the species. Seldom (Figs. 2, 

 3, 4) the process is practically naked. In one case (Fig. 

 1) it is naked as a whole, but armed with two strong 

 bristly pencils before the apex, quite unlike anything to be 

 seen in any of the other species. 



A comparison of the characters presented by this 

 segment in different species of the Group seems to me to 

 furnish rather important evidence as to the precise degree 

 of affinity in which certain of these probably stand to 



