Contribution to the life history of Orina tristis. 257 



distinct, but these, with the legs and wings, are thickened 

 and fleshy (compared with the imago), but present no 

 spines or other definite armature except a few fine brown- 

 ish hairs on the upper outer exposed aspects of the femora. 

 The ventral aspect of the abdomen is equally smooth, but 

 dorsally all the segments have a greater or less supply of 

 short pale brown hairs. Over the front of the head and 

 the prothorax these are especially regularly and thickly 

 scattered. The prothorax is a large, somewhat square plate, 

 5'5 X 4'5 mm., as in the larva and imago. The meso- 

 thorax is narrow, 1'3 mm., with a projecting angle at centre 

 of its posterior margin; just in front of this is a small 

 raised boss, which carries a few, the only, hairs on the 

 segment. The metathorax is again rather wide, 1'7 mm. 

 (the projecting point of mesothorax makes these measures 

 unduly favourable to that segment), with a dorsal longi- 

 tudinal grove, it is very smooth and poHshed, and possesses 

 only some half-dozen scattered hairs on each side, two on 

 either side near the middle of the hind marffiu being 

 especially strong. 



The first abdominal segment is narrow (about 0"6 mm.), 

 and has a central dorsal grove, which on the second is 

 replaced by an elevation, the remainder having no dorsal 

 peculiarity. The first six abdominal segments are narrow 

 (about 5"0 mm. together), each however rather broader 

 than the one in front. The next is longer (2'0 mm.) and 

 is apically produced to an angle. Each of these (1-7 

 abdominal) has a spiracle, a small round chitinous ring, 

 about I'O mm. across, below which the dorsum of the 

 segment is rounded off, forming a lateral flange. 1-6 

 carry a fringe of hairs along their posterior margins, which 

 are carried round the margin of the flange, and where more 

 especially they are less a fringe, and more uniformly 

 scattered over the surface. Abdominal 7 has hairs scattered 

 all over it except its extreme anterior margin. 



Dorsally 8 and 9 (abdominal) rapidly taper to a fine 

 brown chitinous point with which 9 terminates, 9 has a 

 very few inconspicuous hairs, on 8 they are more numerous 

 and evident but less so than on 7. 



Ventrally 8, 9, and 10 are marked by sundry elevations 

 no doubt marking the genitation. 



On March 4th, 1903, there still remained alive two 

 males of the beetles taken at Pino on May 30th, 1902. It 

 is not, however, the case that these represent the amount 



