(;. 11. Foui) jo:; 



4. Description of the Larva. 



The full-grown larvae of A. obscurus measure about 19 mm. x 2 mm. 

 (Plate XVI, figs. 1 and 2). They are semi-cylindrical and their colour 

 varies from pale yellowish white, to yellow brown. The young stages 

 are of a paler colour, which darkens as the larvae become older. The 

 freshly-moulted larvae are easily distinguishable by their pale yellow 

 white colour. The junctions of the body segments are of a slightly 

 darker shade than the rest of the body, and are in addition marked 

 with faint longitudinal striae (Plate XVII, fig. 6). The spiracles are 

 placed on darker chitinised areas. The muscular impressions of the 

 ninth abdominal segment are strongly chitinised dorsally and ventrally, 

 and slightly so laterally. The legs are of a darker brown colour. 



The head is approximately as broad as long, with the anterior 

 margin of a dark brown, rounded at the angles. On each side of the 

 head, just behind the antennae, but slightly more towards the median 

 line, is a slightly raised, irregularly rounded, pigmented eyespot. Imme- 

 diately behind each eyespot is a long slender seta. The antennae are 

 short (Plate XVII, fig. 10), each consisting of three segments. The first 

 segment is stout, brownish round the base, with a clear area round the 

 summit. The second is dark brown, longer in proportion to its breadth, 

 narrower than the preceding segment, and somewhat enlarged on its 

 outer and upper margin where it bears two stiff upright hairs. The 

 third segment is dark brown, about one half the dimensions of the second 

 segment, and bears two terminal lobes which are slightly lighter in 

 colour than the second segment. The lobes of the third segment, 

 when seen from above, consist of a long narrow lobe (almost as long 

 as the second segment) flattened at the apex, and a smaller lobe placed 

 ventrally to the larger lobe and nearly half as long as, and a little 

 thicker than, the latter. The third segment bears, in addition, two 

 setae. The head region bears two pairs of setae on the lateral margin, 

 placed near the anterior and posterior edges. No attempt is made 

 to discuss the homologies of the head region. 



The mandibles (Plate XVII, fig. 7) are of a dark brown colour, irregu- 

 larly flattened dorso- ventrally, and sickle shaped. The apex is somewhat 

 blunt, and just belo^v this is a blunt tooth on the inner margin. This 

 blunt tooth is common to the genus Agriotes according to Schiodte(i6). 

 A second tooth that is more pointed than the former, projects nearly 

 half way down. Just below, is a well-marked process (la) projecting 

 inwards which is the "lacinia mobilis." Mangan{ii) in describing the 



7—2 



