i86 



Records of the Indian Musetmi. 



[Voi,.XIX, 



Text-fig. i. — Gizzard (4 folds 

 shown) of Megalestes major. 



Mr. Tillyard has pointed out to me that these larvae, which 

 I had previously identified from an examination of the venation, 

 are not Lestine but most distinctly Synlestine in their characters. 

 He was able to demonstrate a ver}^ close similarity in structure 

 between the larva of Megalestes and that of the Australian 

 genus Synlestes. Hence it is necessary to remove the genus Mega- 

 lestes from the neighbourhood of testes and refer it to the subfamil^^ 

 Synlestinae as defined by Till3'ard [The Biology of Dragon/lies, p. 

 277). The subfamil}^ will then include three genera : — Synlestes 



from Australia, Megalestes from 

 India, and Chlorolestes, which is 

 African. Needham has already des- 

 cribed an unidentified larva of large 

 size from India, which in important 

 respects {e.g. structure of mask and 

 caudal gills) is clearly related to 

 Megalestes, though belonging to a 

 larger insect. There is only one 

 known Indian genus, Orolestes of 

 Maclachlan, to which this larva can 

 be assigned with any degree of probability ; and in respect of details 

 of venation, as noted by Needham, this ascription is very reason- 

 able. Moreover, Mr. Tillyard has recently examined the type speci- 

 men of Orolestes selysi Macl. in the Maclachlan collection, and in- 

 forms me that the species is a true Synlestine ; so that when the 

 identification of the larva is settled" the genus must in all pro- 

 bability be added as a fourth to those of the subfamily. (See 



Needham, Entomol. News XXII, 

 191 1, pp. 342—344, pi. xi, figs. 1—4.) 

 I quote here Tillyard's definition 

 of the larva of the Sj^nlestinae 

 {Biology of Dragonflies , p. 277). 



'' Larva very slender and elong- 

 ' ' ated , with exceedingly long 

 '^ spider-like legs, mask with in- 

 " cised median lobe, lateral lobe 

 '' narrow, cleft into two sharp 

 '' teeth and with a denticulate inner 

 ' ' border ; movable hook long and 

 '' slender ; no setae present, antennae with greatly elongated 

 " pedicel, caudal gills with secondary tracheae somewhat oblique 

 ' ' to gill axis. Gizzard with dentition reduced to a few large teeth 

 '^ on each field." 



This definition was drawn entirely from the larva of Synlestes, 

 but it will be evident that the Megalestes larva (and also Need- 

 ham's larva) show a close approach to the same t3^pe. 



The measurements of the largest of the three larvae of Mega- 

 lestes major (final instar ?) are as follows : — 



Total length 19-5 mm. ; gills 575 mm. additional ; abdomen 



Text-fig. 2. — Labium 

 Megalestes major. 



of 



