igog.] J. G. Needham : Notes on the Neuroptera. 207 



layer is irregularly woven, with stay threads extending to all 

 the high places in the dried sponge mass, in the hollow of which it 

 nestles. 



The larva of this species is 4-5 mm. in length, and i mm. in 

 width, and its suctorial setae are as long as the head and thorax 

 together and somewhat longer than the setaceous antennae. The 

 seise on the middle abdominal segments are rather more closely 

 sessile than in the other larvae of Sisyra hitherto described, but 

 otherwise apparently similar. Some of the larvae sent me by 

 Dr. Annandale were taken by him from osteoles of Spongilla 

 alba. 



Dr. Annandale has sent me the following notes on the habits 

 and ethology of this species : — 



''I am now able to send you larva, pupa and adult of the 

 common sponge Sisyra of Calcutta. This species is common 

 in the canals of Spongilla carteri, one of our most abundant 

 freshwater sponges in India. I have only found the larvae between 

 August and March, that is to say in the rains and cold weather, 

 but the sponge as a rule dies in the hot weather. The larvae vary 

 from green to white in colour, and can usually be discovered 

 clinging to the walls of the oscula and larger canals of the sponge, 

 in which these structures are more patent than they are in most 

 Indian species. The proboscis seems to be inserted into the 

 substance of the cells of the host, and if the sponge is green, the 

 contents of the stomach of the parasite are also green. If the 

 sponge dies, and the water becomes foul, the parasite forsakes it ; 

 and I have even found a few individuals among filamentous algae 

 in the tanks. The mode of progression adopted, when the insect 

 is at large, is either that of crawling slowly on a solid support 

 or that of swimming through the water by means of movements 

 of the abdomen. The thorax is held vertically upright, in the 

 latter case, with the head flexed a little downwards and the 

 abdomen strongly upward; so that the whole animal has the 

 outline of an S when seen from the side. The abdomen is alternately 

 approximated to and removed from the thorax with great rapidity, 

 and these actions bring about a forward movement. I could not 

 observe any regular movements on the part of the jointed gills, 

 but apparently they aid in supporting the insect upright in the 

 water. 



''At the beginning of March a great number of specimens of 

 Spongilla carteri] being attached to the ends of hanging branches 

 and in similar situations, are left high and dry, as the water 

 evaporates from the tanks. In the circumstances the larvae, 

 sooner or later, leave the interior of the sponge, in which they 

 sometimes continue to live for some days after it has been left dry, 

 and pupate in hollows on the external surface. A flimsy cocoon 

 of white silk, covered and fixed by a loose web of the same 

 material, is spun, and the imago emerges in about a week. The 

 imago is very sluggish and apparently takes to flight with 

 difficultv." 



