NATUMAL HllSTUJtY. 



prothorax is much elongated, and the head is rather broad, with prominent eyes. The species, 

 which are of moderate size and not very numerous, are found in all the warmer parts of the world. A 

 single species (Mantispa payatm) is common in Southern Europe. 



FAMILY SIALID^E. 



In this second family of the Planipennia the head is placed nearly horizontally in front of the 

 thorax, so that the opening of the mouth is in its front part instead of beneath. The antennae are 



bristle -shaped or thread-like ; the ocelli are generally 

 present ; the ligula is membranous, cleft in the middle ; 

 the fore and hind wings are similar, except that the 

 former have a more dilated anterior margin. The 

 larvae of all but one exceptional form live in water, 

 and are furnished with branchial filaments on all the 

 abdominal segments ; the pupa is not enclosed in a 

 cocoon. 



The common British species (Sialis lutaria) is a 

 blackish-brown insect rather more than half an inch 

 long ; it is well known as a bait to anglers, and may 

 be found abundantly in the spring and early summer 

 upon walls and palings in the neighbourhood of 

 water, and upon the stems and leaves of grasses and 

 other plants growing in the water or upon its brink. 

 In repose the wings in these insects, as in the 

 Hemerobiidae, are laid together in the form of a 

 roof on the back of the insect. They are sluggish 

 and inactive and do not readily take to flight. The 

 female deposits a great quantity of brown eggs, 

 attaching them in a compact mass to the stems of 

 rushes and other aquatic plants ; the eggs form short 

 cylinders which are attached by one end side by 

 side with great regularity ; and the opposite end is 

 suddenly narrowed and terminated by a small slender 

 point. The larva hatched from these eggs is elon- 

 gated, with a large horny head and powerful man- 

 dibles ; the three segments of the thorax are also horny, but those of the abdomen are soft, and each 

 furnished with a pair of articulated bristly filaments which serve as gills, and also assist the larva in 

 swimming through the water, which it does with facility. The abdomen is terminated by a long 

 bristly tail. When full grown the larva quits the 

 water and burrows into the soil of the bank, where 

 it forms a little cell and there undergoes its change 

 to the pupa state. The pupa is not enclosed in a 

 cocoon, and shows all the parts of the future insect, 

 each enclosed in its separate sheath. It remains in 

 this condition showing no signs of life, except a 



brisk twisting of its abdomen if disturbed, until the time comes for the emergence of the perfect 

 insect, which takes place within the chamber. 



This insect and a few of its immediate allies have no ocelli ; in the rest of the group three 

 of those organs are present and often of considerable size. The species of Corydalis and 

 Chauliodes (Corydalis ccrnutus is a well-known North American species) are distributed over the 

 warmer parts of the world ; the antennae are more or less pectinated, especially in the males, 

 and this sex is also further distinguished by the large size of the mandibles and the presence of 

 a pair of forceps-like appendages at the apex of the abdomen. Their larvae live in the water like 

 those of Sialis. 



SIALIS LUTARIA. 



LARVA AND PUPA OF SIALIS LUTARIA. 



