1«2 



THK lANADlAN KNTWM«»I.<MJIST. 



II. 



Ik'lwecn August 20lh and 271!), in 1905, the Microvelia americatuf 

 in my aciuaria mated and began ovipositing. .A portion of the eggs were 

 attached to the upper surface of some duck-weed floating on the water, 

 while a few were dropped on the surface of the water itself. 'I'he 

 majority, however, were embedded in a colourless waterproof jelly, and 

 fastened in masses to the sides of the aquarium, slightly above the water. 

 Subsequent observations confirm this mode of ovipositing, and in the 

 absence of direct observations in nature, I should say the eggs are deposited 

 on rocks and stones, just above the surface of the water, or else on Moating 

 sticks. 



Ovum. — Kllipsoid in shape ; colour, translucent while, more or less 

 glairy. Under the niicroscoi)e the 

 chorion is seen to be sculptured in 

 irregular hexagons. Dimensions by 

 camera-lucida and scale : .6X.25 mm; 

 .63 X .24 mm.; .6.3 x .22 mm.; .6S x .29 

 nun.; . 7 25 x. 2 7 mm. (Ki^. 12.) 



,\s develoj)ment progresse.'*, the cgi;s grow 

 darker, and at one end the red eyes, the legs, ihe n)C&A'«^M f. ■\ 

 rostrum, etc., of the nymph are visible through 

 the shell. .\l the end of about 17 days the eggs 

 hatch, and the young nymph emerges by a 

 longitudinal slit about two-thirds of the lenijih of '"'*•• '•'•-pv.T of MKrotctia 



° ° amcncaii.-i (x 27). 



the egg, along one side and the end. 



Nymph, -isl Instar : Head, long.: lat.:: 15: 22; eyes: vertex:: 6: 

 10:6; antennal joints, i, 2, 3, 4. 5 : 6 : 5 : 15. 



Antenme 4 jointed, ist curved and stout; 2nil straight, a little 

 stouter than the ist ; 3rd slenderest ; 4th fusiform, slightly slenderer than 

 the 2nd, but as stout or a little stouter than the isi, all thickly covered 

 with long hairs, one long stout hair near the distal end of the ist joint set 

 in a sense i)it and pointing outward ; inserted under the head. Kyes 

 exteriorly rounded, set obliquely in the head, occupying a little over 

 one half the head. Head thickly pilose. Rostrum 4 jointed, rising under 

 the head. Proi)orlions of joints : ji : J2 : j^ : J4:: 26 : 7 : 60 : 40. Tlie 

 second joint is anniiliform, and the 4th darker and apparently more 

 heavily «hitini/ed than the others. The tylus is slightly prominent. In 

 moulting, the lancets are cast with the skin. 



Prothorax clearly indicated, ring like ; long.: lat.:: 5 : 25, in shape 

 something like a curving collar of even width, sides roinided and sloping 



