298 ENTOMOLOGICAL NEWS. [July, '17 



ed at the other. The chorion is roughly shagreened, and 

 under magnification x 975, shows very shallow pits. It has 

 no indications of a lid or line of weakness along which to split. 

 Length, 3 mm. ; diameter, i mm. 



The ova are clear white when first deposited, but change 

 to brown as development of the embryo progresses. In hatch- 

 ing, the nymph emerges through a longitudinal split beginning 

 at the truncate end and running about one-half to two-fifths 

 the length of the egg. Three females gave 30 ova in four days. 

 They were fastened a few on top of a piece of cork in the 

 aquarium, and most in a clear colorless glue or jelly, along the 

 edges of the cork and under the surface of the water. Gar- 

 man' says the eggs are attached to aquatic plants. Dufour re- 

 marks (op. c. p. 347) 'T have kept in vessels of water with 

 water plants pregnant females of Gerris pallidum, and I have 

 assured myself they deposit their eggs one after the other, 

 but not in contact, in a kind of mucilaginous jelly." 



After eight or nine days the little bugs emerge. On June 

 9, one year, I secured thirty nymphs. Some seemed to molt 

 right away, which I assume to be casting the amnion. In this 

 connection, Dufour also says (1. c.) "I have seen the larvae 

 born and I have sometimes found caught in the opening of 

 the tgg a fine membrane which was doubtless the immediate 

 envelope of the larva, or which covered the interior of the 

 egg-shell." 



This pellicle cast by Gerris marginatus immediately on emerg- 

 ing covers the body legs and antennae, and is extremely hairy. 

 It is so soft it loses its shape completely, although all the joints 

 of antennae and legs are apparent and the tibial combs are all 

 visible. All the tarsi, on emerging, are i-jointed; all claws 

 subapical ; the antennae are ver}' stout, the last joint as long 

 as the others put together, and so far as could be seen in bal- 

 sam mounts, apparently 3-jointed only. The lancets are also 

 cast with this skin. 



It is an open question in my mind whether or not this may 



^189 Bull. Ills. St. Laby. N. H., iii : 172. 



