790 



STUDIES IN AtJSTRAMAN NEUROPTERA, vii., 



known to ine. The reasons for it are two; firstly, that there are 

 onl}^ three or four larval instars in this Order; and, secondly, 

 that no food at all is excreted, the waste-products being stored 

 in a special sac or cham- 

 ber of the alimentary 

 canal, which is not cast 

 out until the emergence 

 of the imago. Hence it 

 is clear that a large in- 

 crease in the size of the 

 abdomen is inevitable 

 during each larval in- 

 star, whereas the size of 

 the head can only be in- 

 creased at ecdysis. 



The head of the young 

 larva is somewhat 

 flattened, trapezium- 

 shaped, and wider in 

 front than behind ; 

 length about 0'6mm., 

 breadth in front about 

 the same. At the two 

 anterior angles, which 

 are somewhat rounded, 

 are the two groups of 

 simple eyes, occupying vv\- — - — 7 

 the area from which the 

 compound eyes of the . ^'"^ " ^'~" 



pupa and imago are latf^r developed. There are five ocelli in 

 each group. The anterior border of the head projects in the 

 middle to form the prominent triangular labrum, on either side 

 of which lie the long, slender antennm, which are eight-jointed. 

 The mouth-parts are very extraordinary, consisting of a pair of 



* Newly-hatched larva of Ps. elegant (Guer.); ( x 30): />, part of hind leg 

 of same, to show tarsal claws and enipodiuni, tlie latter in the form of an 

 elongated process terminating in a sucking-disc; ( x 87)- 



a 



