﻿Theke are various species of this singular insect distributed 

 over the old world, hut I do not remember to have seen one 

 from any part of America ; yet the genera Beloslonia and 

 Naucoris are not uncommon there. The only species found 

 in this country, and I believe I may add in Europe, inhabits 

 ditches and ponds : it moves slowly, and when resting amongst 

 the conferva? or mud at the bottom of the water it is easily 

 overlooked, from its obscure dirty colour ; yet when the wings 

 are expanded, the fine scarlet tint of the back gives it a hand- 

 some appearance. I think there is little doubt that Nepa can 

 flv, yet I never heard of one being detected on the wing. It 

 is' found throughout the year in every stage. The eggs are 

 very remarkable, and resemble the seeds of some Syngenesious 

 plants; they are deposited in a string, embracing each other 

 by seven rays surrounding the apex, which close upon the base 

 of the one before it. 



These insects, like Ilanatrn linearis (pi. 281.), are carnivo- 

 rous, and live, I believe, in their diifcrent states, upon other 

 insects and small animals, such as tadpoles, whether dead ov 

 alive: they are provided with powerful anterior legs, peculi- 

 arly adapted for seizing upon the larva,^ and pu});e of other 

 aquatic insects, more active than themselves, which are speed- 

 ily despatched by their strong proboscis. Like other insects 

 inhabiting the water, their antennae are small, and their situa- 

 tion is similar to that of the flea, lying in cavities immediately 

 behind the eyes. The filaments forming two tails are for the 

 purpose of respiration when the insects are under water. 



In the 7th volume of the " Annales Gcnerales des Sciences 

 Physiques" is an elaborate and curious memoir, by Mons. 

 Leon Dufour, detailing the anatomy and organization o^Ncpa 

 cinerea and Raiiatra linearis, which are said to be very remark- 

 able. 



The plant is Sagittaria sagittifolia, Common Arrow-heaii. 



