SIALID^. 



607 



Chaidiodes pecfhucornis Linn., our most common species, is 

 yellowish ashen, with reddish pectinated antenna?. In C. ser- 

 ricornis Say the antennae are serrate. In Corydalus, the largest 

 form known, the pro- 

 thorax is square but 

 narrower than the head 

 and the antennte are 

 stout but filiform. The 

 male of C. cornutus 

 Linn. (Fig. 594, fe- 

 male ; fig. 595, male ; 

 fig. 596, pupa; fig. 597, 

 larva), has very long 

 mandibles, about twice 

 as long as the head, 

 whence its specific 

 name. According to 

 the Editors of the 

 " American Entomol- 

 ogist," the eggs of 

 this insect (Fig. 598) 

 are "oval, about the 

 size of a I'adish seed, 

 and of a pale color, 

 with some dark mark- 

 ings. They are usu- 

 ally deposited in a 

 squarish mass upon 

 reeds or other aquatic 

 plants overhanging the 

 water." Hagen does 

 not " think that the 

 lateral filamentous ap- 

 pendages ai-e connect- 

 ed with respiration ; 

 the little sponges at ^'S- ^^*' 



the base of the filaments and a little behind them are the ti-ue 

 branchiic." "The reason that the lai'va of Corydalus has both 

 branchiae and spiracles is, that it lives, like Sialis, some weeks 

 out of the water before its transformation." (Hagen.) 



