FAMILIES LIBEI.Ll'I.ID.IE AND MYRMELEONID^. 185 



The libellulse are widely extended in their distribution : they are vorarioiis in their 

 habits, of strong muscular powers, and able to remain Ions; iipon tlie wing. Tluir larvrc 

 are quite as voracious as the jierlect inseet. The female deposits her eggs on tlie water, 

 while upon the wing. They may lie regarded as serviceable to man, especially in their 

 perfect state, by Imling upon insects that are annoying, as musfjuitoes and the like. 



The family lias b»>en subdividwl into three genera by F^abricus : 1. Lieei.lula proper, 

 with wings horizontal when at rest, eyes large and af)proximate,and having also the three 

 ocelli ; the middle division of the lip is the smallest, and the aUlomen is ensiform. The 

 second genus is /Eshna, having two ocelli situated on a transverse keel-formed elevation ; 

 the intermediate lobe of the labium larger than the lateral, and armed with a strong tooth 

 and a spinous appendage ; abdomen narrow and elongatetl. The third genus is Acnws : 

 it carrier its wings perpentlicularly when at i-est ; the middle lolx- of the labium divided 

 in two ; the antenna^ with four articulations : there is no vesicle upon the forehead ; the 

 ocelli are equal, and the alxlomen filiform. 



LiBELLULA PULCHKLLA. ( p]atc XV, fig. 5.) 



Color black. Abdomen .sometimes wholly black both above and below, and sometimes 

 light slate above and black below, or partly slate color : individuals seem to vary in 

 this respect without regai-d to sex. Wings marked by three black or dark brown spots 

 or bars : the basal is confined to the costa,and does not extend to the posterior edge ; 

 the external covers the apical area, and sweeps around so as to form a circular curving 

 edge towards the base. 

 Fig. 4 is closely allied in its habits and appearance to the pukhella, and its abdomen 

 presents in dilferent individuals the same varieties of color. 

 Fig./. Larva of the Llbcllulu. 



3I}Tmelconidae. 



( Plate sxxiii, figs. 4, 5, 6 7 ) 

 A FAMILY of insects familiarly known under the name of anf-lions, while in the larva 

 state. The insect has always arrested the attention of the curious, from its peculiar habits 

 the singular form of its larva, and the ingenuity it displays in making traps or pitfalls 

 to catch the prey that must serve for its sustenance. In its perfect state, it resembles a 

 LiBELLVLA ; but whcH it is in its larval form, we would by no means suspeet that it 

 belongs to, or is the embryo of one of the most beautiful of the insect tribes. There is 

 always, however, a wide difference between insects in these two states. 



In the family of the Libellulidje, the larva is aquatic, and is provided with the ne- 

 cessary form of mouth and mandible to seize and devour other insects : it is in fact a 

 voracious animal, an.l carries on its depredations in the water; while in the Mviumello- 

 [ Agkicoltobal Kepokt — \'ol. v.] 24 



