98 AJ\r J ceo UNT OF BRITISH FLIES. 



the larvae of Chirononuis by Osten Sacken,* in Culex by Pallas,t as 

 long ago as 1782, and also in the larvae of Tipula oleracea by Main.J 

 These are the only records of any importance I can find. But in 

 the Alycetophilidie this phosphorescent character has been more fully 

 observed. It was first noticed by Wahlberg,§ who, whilst studying 

 the transformations of Ceroplatus sesioides, saw a bright light emitted 

 by the larva and pupa, but not by the perfect insect. More recently 

 some interesting papers have appeared in the Fntomo/ogist's Mo/ith/y 

 MagazineW by Hudson and Osten-Sacken, These luminous larvce, 

 described by Hudson, came from New Zealand. According to one of 

 the best authorities, Osten-Sacken, they were the larvae of Sciophila^ 

 certainly those of one of the MycetophilidcE. The vividness of the 

 light produced is best described in Mr. Hudson's own words : " The 

 light from a single individual kept in a caterpillar cage may be seen 

 streaming out of the ventilators at a distance of several feet." He 

 describes it as coming from a gelatinous knob at the posterior ex- 

 tremity of the larva. Those who are interested in phosphorescent 

 insects should read " Les Insectes Phosphorescents," Henri Gadeau 

 de Kerville. Rouen, 1887. 



Internal Anatomy of Ceroplatus^ and Mycetophila. 



The alimentary canal has two salivary glands opening into its 

 proximal end, close to the mouth. Each gland is a slender, single 

 tube, one on each side of the canal. In Mycetophila these glands 

 are composed of large secreting cells with a dark nucleus. The 

 duct of the gland is very fine, and is a simple tubular structure, the 

 cells being more regular and clearer than those of the glandular part. 

 The mouth opens into an a-sophagus, which is short in Ceroplatus^ 

 but of moderate length in Alycetopliila. The crop is oblong, with 

 simple walls and with a small tubular neck in Ceroplatus. In the 

 Mycetophila I examined there seemed only a slight constriction 

 between the oesophagus and crop. The Chylific ventricle is long and 

 cylindrical, and commences from two lateral conical, sack-like ca^ca. 

 These two caeca I was unable to find in the flies I examined, but 

 Uufour found them in Ceroplatus. There are four hepatic cwca, 

 which open into the base of the chylific ventricle. The i/itestine is 

 small and the walls appear to be smooth, ending in a somewhat 



* Ent. Mo. Mag., 1878, xv., p. 43. 



t Kleine Notizen in den neuen Nordischen Beitragen, 1782, t. iv., p. 396. 



X Mag. Nat. Hist., 1837, p. 549. 



§ Act. Holm., 1838, and Stett. Ent. Zeit., 1849 (trans.). 



I! Ent. Mo. Mag., vol. xxiii., pp. 99, 133-230. 



IT Dufour, Anns. des. Sc. Nat. T. xi., 1839, pp. 193-213, pi. 5. 



