410 Syrphidae. 



198), and the larva (of tenax and the American species dimidiatus) 

 are mentioned as passing from the intestine of man (Riley and How. 

 Ins. Life, II, 1889, 262). The developmental stages of E. arbustorum 

 are described by Bouché (Naturg. d. Ins. 1834, 54, Tab. V, Fig. 14), 

 and thoroughly described and figured by Trybom (1. c. 76, Tafl. II) ; 

 Zetterstedt mentions this larva (1. c. 660) and in XI, 1855, 4651 he 

 notes that about 50 specimens of the larva had passed from the 

 rectum of a boy, and Wagner (Stett. ent. Zeitg. XXXI, 1870, 78) men- 

 tions a similar observation. The larva of E. nemorum is probably 

 among those described by Reaumur (1. c. Tab. XXXI, Fig. 8), and it 

 is mentioned by Meigen (Syst. Beschr. III, 1822, 395). The larva of 

 E. horticola is mentioned by Trybom {flavocinctus Fall. 1. c. 76). The 

 metamorphosis of E. sepulchralis is thoroughly described by v. d. Wulp 

 (Mém. d'Entom. publ. par le Soc. Ent. de Pays-Bas, I, 1857, 18, PI. I, 

 fig. 1 — 2). I have myself, besides larvæ of undetermined species, ex- 

 amined pupæ of E. sepulchralis taken below reeds at the shore on */4, 

 developing at the end of April, and taken on ^^/4, developing in May, 

 and pupæ taken as larvæ below sea-weed on sand at the shore on 

 2^/7, developing in August; pupæ of E.aeneus taken as larvæ at the 

 same date and under the same circumstances as the latter, and like- 

 wise developing in August ; further a pupa of E. lucorum taken in a 

 fen on ^k and developing in the same month; pupæ ot E. tenax isken 

 at horse-dung in a stable on ^^h and developing on ^''/it — ^'^h ; a pupa 

 of E. intricarius taken at a ditch first in August and developing soon 

 after; a pupa of Æ. anthophorinus taken in a fen in April and developing 

 on ^/s ; pupæ of E. arbustorum taken in a cloaca on ^/s and developing 

 at the middle of this month, and fmally a pupa of E. nemorum taken 

 at a lake on ^^,'7 and developing soon after. The metamorphoses are 

 thus more or less known of the foUowing species : sepulchralis, aeneus, 

 lucorum, tenax, anthophorinus, intricarius, arbustorum, nemorum and 

 horticola. 



The larvæ are of the well known shape term ed rat-tailed larvæ 

 (vers å queue de rat Reaumur). The larva (of an undetermined 

 species, I think arbustorum or intricarius) has a cylindrical body, not 

 attenuated in front but a little attenuated behind before it goes over 

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

 ments, the head included; this latter is small and retracted; above 

 the mouth opening are two small, two-jointed organs, the antenna-like 

 papillæ or so-called antennæ, the last joint bearing two small papillæ; 

 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 some- 

 what transversely corrugated above, and the prothoracal segment has 



