9738 Insects. 



In this position she remains for a few seconds, and then suddenly gives a kick with 

 the two hind legs, and you see her running down the ladder, a bubble o a.r enclosmg 

 her abdomen, which it usually resembles in size : the size of the bubbles, however, 

 variable, and it is noticeable that when large the animal throws back and arches the 

 two hind legs so as to inclose and protect it. Water spiders, even if without nests 

 frequently come to the surface of the water in order to breathe, or to change or replenish 

 the supply of air which surrounds the body. In this latter case the apex of the abdo- 

 men is merely thrust out of the water, and after a time drawn back again, the coatmg 

 of air being the same in quantity as before. The only difference in the method of ob- 

 taining the nest and that of the breathing supply, appears to me to consist in the k.ck 

 given by the hind legs when a larger quantity of air is wanted than m\\ naturally 

 adhere to the body. The raUonale of the process is, I think, as follows -.-The body o 

 the spider is clothed with a fine pubescence possessed of air-retain.ng properties It 

 by any means an addiiional quantity of air can be isolated and submerged it will, by 

 tile force of the attraction of cohesion, combine and adhere to that already surrounding 

 the body of the animal. When the spider comes to the surface for this purpose, she 

 thrusts the apex of the abdomen out of the water, thus causing a cavity or depression 

 on the surface: this depression represents the bubble she wants, and only requires its 

 conneciiou with the air above cutting off to enable her to carry it down ; this she 

 effects by the sudden kick given by the bind legs, which, coming from opposite direc- 

 tions, cut off the connection by their scissor-like action. One peculiarity o( the water 

 spider, which I think deserves mention, is the whitish liquid sometimes projected into 

 the water, and which falls slowly to the bottom iu graceful festoons, resembling, more 

 than anything else that I can call to mind, a faint trace of the nitrate of silver test lu 

 a weak chloride solution. I am sorry I cannot give the exact time of incubation, as 

 I left home a little before the eggs were hatched, and when I returned I found the 

 voung spiders set up in life for themselves, each with its miniature air supply and 

 nest The female, at the close of the period of incubation, built for herself a nest like 

 the males, at the top of the jar.-JoArt Peers; BuUermarkel Street, Warrington, 



Avgust 2,\865. ..•,■71 



£rra<«m.-Pleasc to correct the following error in my last communicatiou (^ool. 



9698) ; line 1 Ith, foe " run" read " vest." —Id. 



Notes on and Description of the Larva of Eupithecia plumbeolata, Haw.-Last 

 summer, through the kindness of an entomological friend, I had the pleasure of 

 inspecting a most beautifully executed collection of coloured drawings of various 

 species of Geometra and their larvae, the work of a continental entomologist, M. Carl 

 Plolz. This gentleman figured the larva of Eupithecia plumbeolata. Haw., feedmg 

 on the flowers of the purple cow-wheat (Melampi/rum arvensc). As M. pratense, 

 another species of this genus, grows plentifully in those localities where E. plumbeo- 

 lata is taken in this country, it occurred to myself and several other eutomological 

 friends that this plant might probably turn out to be the pabulum of this species, and 

 we determined in the course of the present season to investigate the matter. I am 

 happy to say that our investigations have proved successful and our suspicions cor- 

 rect About the end o( June I received eggs of E. plumbeolata from Mr. Barrett, of 

 Haslemere, Mr. Hodgkinson, of Preston, and Mr. George Baker, of Derby. The 

 parent moths were all taken flying over or amongst Melampyrum pratense, and had 



