136 THE UNIVERSITY SCIENCE BULLETIN. 



they beat a hasty retreat ; but if it quiets but for an instant, they are on 

 it again, piercing it at the joints of the legs or in the sutures between the 

 segments, until the victim of their voracity perishes, exhausted by its 

 struggles and unable to overcome the actively poisonous saliva Microvelia 

 injects. 



DESCRIPTION OF STAGES. 



The following are taken from Bueno's paper: 



The Egg. 



"Size. Length, .6-.725 mm.; width, .25 mm. to .27 mm. 



"Shape. Ellipsoid. 



"Color. Translucent white, more or less glassy. The chorion sculp- 

 tured in irregular hexagons." 



First Instar. 



"Size. Length, .75 mm.; width, .42 mm., measured from living bug. 

 Head, long.: lat. :: 15:22; eyes: vertex :: 6:10:6; antennal joints 1, 2, 

 3, 4, 5 : 6 : 5 : 15. 



"Antennae 4-jointed, 1st curved and stout; 2d straight, a little stouter 

 than the 1st; 3d slenderest; 4th slightly slenderer than the 2d, but as 

 stout or a little stouter than the 1st, all thickly covei'ed with long hairs, 

 one long stout hair near the distal end of the 1st joint set in a sense pit 

 and pointing outward; inserted under the head. Eyes exteriorly rounded, 

 set cbliquely in the head, occupying a little over one-half the head. Head 

 thickly pilose. Rostrum 4-jointed, rising under the head. Proportions of 

 joints: jl : j2 : j3 : j4 : : 26 : 7 : 60 : 40. The second joint is annuli- 

 form, and the 4th darker and apparently more heavily chitinized 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 rounded and sloping 

 forward, thickly pilose. Prothorax and mesothorax fused into one, but 

 an effaced suture visible between them; thickly pilose. 



"Legs: First pair shorte.«t, 3d longest. All tarsi single-jointed, claws 

 long, simple, slender, subapical, extending as far again from the tip of 

 the tarsus as the tarsus projects beyond the insertion of the claw. Coxae 

 and trochanters much elongated in the third pair. First tibiae with two 

 combs, second with one, apically situated; third tibia with a long, stout 

 subapical spine. First pair of legs, femur longest, then the tibia, then 

 the tarsus, which is stouter than the other two; second pair as the first; 

 third pair, tibia longest, femur next and stoutest, then tarsus, which is 

 more slender than either; all covered with long hairs. 



"Abdomen oval, segments well marked, genital segments prominent; 

 all the segments dark, except at the connexivum, which is wholly light; 

 eight apparent segments. The spiracles are seemingly not to be found 

 in this instar, not being visible in either the entire nyinph or in the cast 

 skins mounted in balsam, even at a magnification of 530. This, of course, 

 is not a proof that they do not exist, but rather shows how well they are 

 concealed." 



Second Instar. 



"Size. Length, .9 mm. ; width, .55 mm. ; balsam mount. 



"Proportions of head: long.: lat.: : 7 : 10 : eyes : vertex : : 14 : 32 : 14; 

 antennal joints, 1 : 8 : 9 : 20; rostral joints, 9 : 3 : 13 : 10. 



"The rostrum extends to the base of the prosternum, or to the inser- 

 tion of the first pair of legs. 



"Prothorax, lat.: long. : : 38 : 6. 



"First pair of legs stouter than the other two; the tarsal combs of the 

 first and second pair as before; the third tibiae armed with a stout double- 



