76 H. C. EFFLATOUN. 



Verrall who considers that all attempts to split up the European 

 or Palaearctic species into distinct genera have been failures. 



DESCRIPTION : — The larva, as described by Lundbeck has a 

 cylindrical body,a little attenuated behind before it goes over into the 

 long, thin, tail-shaped part ; the body consists of twelve segments, the 

 head included, this latter being small and retracted; above the mouth 

 opening are two small, two-jointed organs, the antenna-like papilla? 

 or so-called antenna?, the last joint bearing two small papillae; there 

 are no mouth-hooks but a pharyngeal skeleton; at each side of the 

 mouth below is a small wart with spines. The body is somewhat 

 transversely corrugated above, and the prothoracal segment has 

 some longitudinal furrows. The dermis is tough and densely beset 

 with small spinules; besides these clothing spinules there are above 

 on the corrugations some rather larger spines or small warts but 

 they are very slightly pronounced; they are present in the same 

 number and arranged quite in the same way as in other Syrphid 

 larvae so that there are -some on the prothoracal segment, a trans- 

 verse row of six on the second and third thoracal segments and on 

 the first abdominal segment; on the other segments there are two 

 in the middle on one corrugation and two towards each side on 

 the next corrugation ; on the sides there are three on each segment 

 and one quite below on the ventral surface. On the ventral side 

 there are a pair of proleg-like warts, beset with spines, on the 

 prothoracal segment, and then six pairs of prolegs on the six first 

 abdominal segments ; these are beset witli curved spines at the end, 

 especially along the hind margin. The last segment terminates in 

 the long tail-shaped part with the posterior spiracular tube which 

 is telescopically pro-and retractile and able to be stretched out to 

 a very great length. The tail consists of three divisions, the fore- 

 most is a prolongation of the last segment ; it is transversely 

 wrinkled and like the other dermis beset with fine spines ; at the 

 sides of it are four small bunches of hairs at intervals, one at each 

 side at the base, one at the apex and two intermediate, but the 

 distances between them are dependent on the contractions; the 

 next division is thinner, longitudinally striated and with fine, 

 nearly microscopical spines in rows; finally the third division is 

 si ill thinner, more firmly chitinized and brown; it is very finely 

 transversely striated, the end part smooth, and it bears at the apex 

 the spiracles surrounded by eight plumose hairs. The length of the 

 three divisions are dependent on the degree of extension, only 

 when fully extended, they are seen in full length, and when fully 

 retracted the intermediate part is quite hidden in the basal divi- 

 sion and only the end of the third part is seen protruding from 

 the first or basal part, and also this latter part may be somewhat 



