314 Scientific Proceedings, Royal Duhlin Society, 



are also a few spines on the dorsal and anterior margin of the two foremost 

 body segments (see fig. 1). The cuticle of the body is quite smooth, except 

 for the above hooks and a few very minute spines on the ventral surface. 

 The body is ridged or thickened at the junction of the segments. 



Behind the small sensory prominences is situated the mouth (fig. 1 m.), 

 out of which are protruded the mouth-hooks or " mandibles." The eephalo- 

 pharyngeal skeleton (fig. .3 C. Sk), which lies in the mouth and gullet, consists 

 of a number of paired chitinous sclerites. The lateral plates are long and 

 narrow and deeply bifurcate posteriorly (fig. 3 1. p.). The hypostomal sclerites 

 (fig. 5 h. s.) are broad and short and situated between the mouth-hooks and 

 lateral sclerites. The moutli-hooks (fig. 5 m. h.) are short and strong, each 

 having two blunt teeth behind the prominent apex. In the dorsal wall of 

 the gullet and just above the hypostomals, are situated the pair of parastomal 

 sclerites (figs. 5 and 6 p. s.); each has two parts, a broadened basal, and a 

 pointed anterior, part. In the lateral walls of the pharynx, behind the 

 hypostomals, there are two small hook-like sclerites (fig. 5 s.), occupying 

 the same position as similar structures figured by Banks (1912) in several 

 dipterous larvae. 



At the posterior margin of the foremost body segment are situated the 

 pair of anterior spiracles (figs. 1 and 3 A. Sp.) ; each has four branches (fig. 7 a), 

 and the spiracular opening has the appearance of a very fine sieve when 

 highly magnified (fig. 7 b). 



The large tail-segment bears posteriorly the hind pair of spiracles, situated 

 on prominent outgrowths of the segment which project backwards (fig. 1 P. Sp.). 

 Each posterior spiracle has three branches (figs. 8 and 9) ; the spiracular 

 opening is bounded by a thick chitinous ring. The adjacent cuticle has four 

 very peculiar sets of radiating thickened ridges (fig. 9 th.), situated between 

 openings of the spiracular branches, and they probably serve as a protection 

 to the spiracles, admitting air and excluding foreign material when the 

 spiracles are retracted. Tlie anus is situated at the extremity of the minute 

 anal segment which projects ventrally from the spiracular segment just 

 described. This anal segment is strongly chitinised, and a semicircular anal 

 prolog (fig. 1 a. p.) can be seen at each side of the medial slit (fig. 10 a). 



The puparium (fig. 11) is red-brown, about 2-5 mm. long and 1 mm. 

 broad. The posterior spiracles are very prominent at its postei-ior end 

 (fig. 11 P. Sp.), and the larval mouth-hooks can be clearly seen near the head 

 end. The outline of the developing fly can be distinguished in the cleared 

 specimen, showing the contour of the body and the rudiments of the wings 

 and legs. 



