BY FREDERICK A. A. SKUSE. 663 



aiTanged a little above the lateral line, one pair on the first thoracic 

 segment and a pair on each segment of the abdomen except the 

 two last. Pseudopodia on the thoracic division and the last 

 abdominal segment ; the abdominal segments are also provided 

 with minute pads which are evidently to assist progression. Head 

 black, small, retractile, furnished with a labrum, a pair of trans- 

 verse dentate mandibles, maxillae, a somewhat indistinct labium 

 and rudimentary antennae. Perris, in his description of the larval 

 form of S. Gonvergens, notices "a round areola above the insertion 

 of the mandibles which appeared to be the seat of a completely 

 invisible antenna." In giving an account of the larva of S. Bigoti, 

 Laboulb^ne remarks that when disturbed the grubs move them- 

 selves with vivacity; their bodies becoming viscovis when they are 

 seized. They also have the power of stiffening and straightening 

 themselves. As far as I have been able to ascertain comparatively 

 little has been done towai'ds a knowledge of the young stages of 

 the Sciaridie, and but few of their life-histories have been com- 

 pletely worked out. The study of the mouth-parts is regarded as 

 a very difficult one, and there is a considerable amount of uncer- 

 tainty, amongst capable judges, concerning other organs, as is 

 evinced by their discordant opinions. 



As a general rule the larvae are gregarious, and their food is 

 of a vegetable character, though there are instances of their being 

 found in dung. Laboulbene found the larvae above referred to 

 in a flower-pot filled with ordinary manure which was peopled 

 already with the larvae of Aphodius Jimetarius, and he tells us 

 that they prefer that par-t where the manure is most moist. 

 Perris found S. convergens under bark, amidst the excrements 

 and detritus left by the larvae of a species of Toniicus, of which it 

 made its food ; and the same author bred two other species, one 

 from a twig previously inhabited by the larvae of Tomicus ramu- 

 lorum and Anohium longicorne, and the second from a decaying 

 stump full of the dejections and detritus of other larvae. A large 

 number of larva? mentioned by Winnertz in his monograph of 

 the family were obtained from under the bark of trees, in decaying 

 vegetable matter, old wood ; others were found in manure 



