474 NEUROPTERA CHAP. 



curious nature, and usually attract more attention than do the 

 creatures they serve to protect. 



The Phryganeidae form the division or series Trichoptera ; 

 the two terms are therefore synonymous ; those entomologists 

 who consider these Insects to form a distinct Order use the latter 

 appellation for it. 



The perfect Insect, though the wings are usually ample, has 

 but feeble powers of flight, and rarely ventures far from the 



water it was reared in ; it has a moth- 

 like appearance, and the wings in 

 repose meet, at an angle, in a roof-like 

 manner over the back (Fig. 326, E). 

 The head is small, with the front in- 

 flexed ; it has two large compound eyes, 

 ~1 ' and usually three ocelli; the antennae 



FIG. 32Q.Hydroptaa angusteiia are slender, thread-like, and occasionally 



attain a great length. The parts of the 



mouth are very peculiar, the labrum and the palpi especi- 

 ally the maxillary palps being well developed, while the 

 lobes of the maxillae and labium are amalgamated and therefore 

 indistinct. The labrum is more or less elongate, and is more 

 mobile than is usual in mandibulate Insects ; it is held closely 

 applied to the maxillae. These latter are small, have usually 

 only a single small free lobe ; they are united to one another and 

 to the labium by membrane in such a manner as to form a 

 channel along the middle of the mouth, the labrum forming the 

 roof of this channel. The palpi are in some cases (Sericosto- 

 matides) of a remarkable nature ; their joints vary in number 

 from three to five, and differ sometimes in the sexes of the same 

 species. The lower lip appears as a plate supporting the labial 

 palpi, which are three-jointed and do not exhibit any peculi- 

 arities of structure comparable with those we have mentioned as so 

 frequently existing in the maxillary palps. Difference of opinion 

 exists as to the mandibles, some entomologists declaring them to 

 be entirely absent, while others state that a small tubercular pro- 

 cess that may be seen in some species on each side of the labrum 

 is their representative. The prothorax is very small, the notum 

 is the largest piece but is quite short, the side-pieces are very 

 small, and the sternum appears to consist only of membrane. The 

 mesothorax is much the largest segment of the body; its sternum 



