A. W. Rymer Roberts 201 



about twice the length of the anterior. The prothorax has a further row 

 of short hairs rather variable in number close to the anterior marginal 

 border. The ventral surface of the thorax is bare save for three pairs of 

 short hairs on the prosternum. On the abdominal sternites 1-8 three 

 rows are present bearing four, two, four hairs respectively. 



The single pair of thoracic spiracles is situated in the pleurae of the 

 mesothorax ; those of the first eight abdominal segments near the lateral 

 margin of the tergites a little behind the anterior margin (Plate IV, fig. a). 



The abdominal segments gradually increase in size from the 1st, 

 which is the smallest, to the 9th. 



The muscular impressions, present on the abdominal segments of 

 most Elaterid larvae, can hardly be made out in this genus; the longi- 

 tudinal branch can, however, sometimes be seen behind and somewhat 

 dorsal to the spiracle, running nearly parallel to the lateral suture. 



The 9^/i abdominal segment is considerably longer than the preceding 

 one, conically paraboloid (as Benng(2) aptly describes it), with a pair of 

 large open pits, margined with brown, situated one on either side near 

 the anterior margin of the tergite (Plate IV, fig. a). In life they are nearly 

 round, but contract at the sides to an elongate oval shape when pre- 

 served in spirit. Their margin of stout brown chitin is somewhat raised 

 above the general area of the tergite on either side. Within, the pits are 

 Hned with pale membrane, which bears numberless minute dark hairs 

 arranged over the entire surface. Similar fine hairs are also found on the 

 inner surface of the chitinous rim just mentioned. In consequence of 

 the presence of these hairs situated within the pits, the latter are pre- 

 sumed to have a sensory function, though what it may be has not yet 

 been ascertained. Formerly, they were wrongly supposed to be spiracles, 

 but more recently they have been referred to as muscular impressions by 

 IIenriksen(7) and Schi6dte(i2). 



From the posterior margin of each of these pits an almost straight 

 suture runs backward, terminating beyond the middle of the segment, 

 shghtly more dorsal than the sensory pit. Situated between these two 

 sutures is another pair of parallel sutures, arising and terminating at 

 corresponding points of the tergite (seen in Plate IV, fig. h). 



The apex of the segment is brown and is shghtly produced into a 

 stumpy Cauda. 



The 9th tergite (Plate IV, fig. a) is continued uninterruptedly on the 

 ventral surface for about half its length posteriorly, while the 9th 

 sternite, which is an arch-shaped area and contains the pseudopodium 

 near its apex, is separated from the tergite by a deep and brownish 



14—2 



