4a) HAL stem, at a. I.KPiDOFi'KKA. 



ciliated in the males: head small, smooth between the antenna: thorax 

 moderate : tvings forming a triangle during repose; anterior elongate, acute, 

 subtruncate on the hinder margin, of nearly plain uniform colours, without 

 transverse streaks; posterior ovate-triangular, entire, adorned with a dark 

 border : abdomen slender, and attenuated behind in the males, with a tuft 

 at the apex, rather stout, and acute at the tip in the females : legs very 

 slender, rather long; posterior tibiae with two pair of spurs. Larva with 

 sixteen legs ; feeds on aquatic plants : pupa inclosed in a cocoon, formed of 

 conglomerated pieces of the food of the larva, united with silk. 



The minute maxillary palpi and distinct labial ones of the insects 

 of this genus, exclusively of the almost rudimentary maxillae, the 

 beautiful simplicity of the colouring on the wings, the posterior ones 

 being adorned with a dark margin studded with ocellated spots, serve 

 as characters to distinguish them from the Hydrocampse, with which 

 they are associated by Latreille and others. 



Sp. 1. Lemnata. Alis anticis niveis (^JietntJice elongatis fusco adspersis) puncto 

 atro, posticis aJbis fascia marginali nigra, punctis 4 — 6 argenteis. (Exp. Alar. 

 $, 8 — lOlin.; 9 8 lin. — 1 unc.) 



Ph. Ge. Lemnata. LinnL — Donovan, viii. pi. 266. /. 1, 2. — Hyd. Lemnata. 



Steph. Catal. ii. 165. No. 6801. 



Anterior wings in the male snow-white, in the female narrow and elongate, of 

 an ashy hue, with fuscous atoms, in both sexes with a minute black dot in 

 the centre, most evident in the male; in which sex the hinder margin has 

 an ashy-brown fascia, not reaching to the costa : posterior wings white, 

 with a black dot, and clouded with dusky atoms, forming a kind of oblique 

 streak in the females ; the hinder margin with an abbreviated bluish-black 

 fascia, in which are from four to six minute silvery spots, most numerous in 

 the females. 



The male is sometimes entirely snow-white; and the markings in both sexes 

 vary considerably in intensity. 



The caterpillar feeds on duckweed {Lemiia) and other aquatic plants ; it is of 

 an olive-brown, with a reddish-brown lateral stripe, the head small: it 

 changes into pupa in small elevated follicles constructed of the lemna by 

 itself, and in this it remains about a fortnight: the imago appears about the 

 middle of June, abundantly. 



Extremely abundant in ditches and ponds where Lemna grows, 

 throughout the metropolitan district. " Cambridge."— C. C. Bahing- 

 ton, Esq. " Fens of Cambridge, common." — Rev. L. Jenyns. 

 " Epping."— Mr. //. Donhleday. 



