1913-] m;. Bezzi : Indian Trypaneids (Fruit-Flies). 61 



the adaptations in this way are very numerous and different. The eggs are elongate, 

 cylindrical, rounded at the two ends, whitish, and with a smooth and thin shell; in 

 microscopical observation the micropyle at the cephalic end appears as a prominent 

 tubercle. 



The larvae in the last stage are whitish maggots, with a round and conical body, 

 pointed in front and abruptly truncated behind. They are divided into a number 

 of segments, which are not always easily distinguished, but are usually 14 in number, 

 those of the cephalic end being very small. The body is smooth above ; the under 

 surface bears transverse rows of small black spines, directed backwards; the sides 

 are usually adorned with little prominent ring-like keels. The anal end is somewhat 

 impressed, contoured by a variable number of fleshy points or tubercles, some of 

 which bear also chitinous spines. 



At present no comparative study of Trypaneid maggots, with the object of 

 discriminating the genera and species, has been made, but the larvae offer a 

 great many structural variations, which can be very well employed for this distinc- 

 tion, variations which will also throw some light on the systematic affinities and 

 classification of the genera of the family. 



The most important features of the larvae are to be found in the antennae and 

 palpi, in the mouth parts and in the spiracles. 



The antennae are short, two- jointed prominences, usually placed in the middle 

 of the anterior portion of the first segment ; the form and length of the two joints 

 are variable in the different species. The palpi are placed just below the antennae 

 and in front of the mouth booklets and are also variable in shape. 



The mouth parts are very important and form the so-called ''pharyngeal 

 skeleton," which on account of its black colour and of the transparency of the 

 teguments is easily seen. In the larva of the last stage the pharyngeal skeleton is 

 formed by the two thick and strong hooks, prominent and retractile, which represent 

 the mandibles; the internal portion is constituted by the two pharyngeal plates, the 

 upper and the lower, on which are inserted the muscles for their movements. 

 The hooks vary in shape and curvature, in length and thickness ; and below 

 the pointed end they bear sometimes a projecting tooth-like point (present for 

 example in Rhagoletis^ wanting in Zonosema). The plates are also very variable in 

 form. 



The larva in the last stage is amphipneustic, viz., presents only anterior and 

 posterior spiracles. The anterior spiracles are placed on the sides of the third 

 segment ; they are of very small size and crown-shaped ; in microscopical examina- 

 tion they appear to terminate in a variable number of finger-shaped processes. 

 The posterior spiracles are of greater size and are placed on the last segment over 

 the anal opening, near the dorsal surface. They appear as two small yellowish or 

 brownish approximated tubercles, more or less prominent, each of which bears at 

 the end a plate with three respiratory areas. 



The larvae of some species are provided with the faculty of jumping. 



The larvae of the Trypaneids are rather various in their habits, and attack 



