THE CADIS-FLIES. 215 



three ocelli, two on the crown of the head, and a 

 third between the bases of the long, slender, setiform, 

 and many-jointed antennae; and the legs are long, 

 with the tibiae spurred at the tip, and sometimes near 

 the middle, and terminated by five-jointed tarsi. 

 They are usually of a pale brown or greyish colour, 

 rarely variegated in any way; but many of the species 

 present a considerable resemblance to Moths, and so 

 close is this in some instances, that I have known 

 collectors of Lepidoptera bring home specimens of a 

 small common black species (Leptocerus niger) with 

 very long horns, supposing it to be a species of moth 

 with which they were unacquainted; indeed both 

 their structure and appearance indicate that the Tri- 

 choptera form a transition from the true Neuroptera 

 to the Lepidoptera. 



Even in the character of their metamorphosis, 

 although they pass the larva state in water, we cannot 

 but see that these insects present some analogy to the 

 Lepidoptera, and especially that the habits of the 

 larvae strikingly resemble those of the caterpillars of 

 some of the very tribe of Moths to which the perfect 

 insects present the greatest similarity. The eggs are 

 excluded by the female in a gelatinous mass, which is 

 retained at the apex of the abdomen for some time, 

 and then deposited upon the stem of some aquatic 

 plant ; and in seeking a suitable place for the reception 

 of this treasure, the female of our largest species, 

 Phryganea grandis, which measures upwards of two 

 inches in expanse of wing, and is of a general pale 

 yellowish brown tint, has been seen to creep down 

 the stems of plants to a depth of a foot or more 

 beneath the surface of the water, and on being dis- 

 turbed to swim vigorously to another resting-place. 



