hungerford: aquatic hemiptera. 137 



pointed spine, apically and exteriorly, and some stout scattered spines in- 

 teriorly, be^nning half-way up to the tibia. The end of the tarsus ex- 

 tends beyond the middle of the claws. 



"The abdomen and other details omitted are as in the first instar." 



Third Instar. 



"Size. Length 1.2-1.32 mm.; width .72 mm. to .8 mm. balsam amount. 

 "Proportions of head: long.: lat. : : 23 : 35 : eyes : vertex :: 7 : 21 : 7; 

 antennal joints, 12 : 10 : 11 : 21; rostral joints, 6 : 6 : 19 : 9 (measured 

 from cast nymphal skin) ; prothorax, lat. : long. : : 6 : 42. The antennas 

 and legs grow comparatively slenderer, but the number of joints does 

 not change. The cleft spine on the outer side, subapically, of the pos- 

 terior tibia? still persists. The other details omitted are as in the pre- 

 vious instars." 



,(cy Fourth Instar. 



Size. 



"Antennal joints, 12 : 9 : 10 : 24; rostal joints, 7 : 6 : 17 : 9. 



"Owing to having nothing but moulted skins, a number of details 

 must be omitted in this and the next stage of the n^-mph. The general 

 form, aspect and coloration are as before, the main changes noticeable 

 being in the increasing slenderness of the legs and antennje. In this and 

 the preceding instars, the spiracles can be seen in the cast skins, 

 as little round openings in the connexivum. In the entire bug I have 

 not been able to locate them. The basal joint of the antennae is stout 

 and curved, as before, and there is no change in the relative thickness 

 among them. The other details are practically unchanged. The first 

 pair of legs is the stoutest, especially as to the tarsi, and these are 

 single- jointed in all the legs." 



Fifth Instar. 



"Size. Length, 2.14 mm.; width, 1.25 mm. 



"Antennal joints, 20 : 13 : 13 : 35; rostal joints, 6 : 4 : 21 : 10. With 

 slight differences, the other details are as before. The tarsi continue 

 single-jointed, with long, simple claws, the posterior tibize are spined 

 toward the end, the spines increasing in number from the femoral to 

 the tarsal extremity, and stout in proportions. The cleft spine mentioned 

 before is still present, but is not so noticeable. In this instar, though 

 still greenish in colour, ^\^th darker spots, lines and markings, the sil- 

 very patches, so characteristic of the adult, first make their appearance. 

 The female can in this instar be already distinguished from the male 

 on account of its larger size, and less prominent genital segments. The 

 males are so much smaller in this instar than the females, that they 

 may be mistaken for njTiiphs in the fourth instar only. The dimen- 

 sions of the njmiph, taken from the cast skins, mounted in balsam, are 

 not quite accurate, as the skins are much distorted." 



Microvelia borealis Bueno. 



Habitat Bueno in his recent paper says it has a limited range, 

 doubtless because little collected. He records it for New York, New 

 Jersey, and says Parshley got it in Maine. The writer found it abundant 

 on the margins of a little pool (Cattail pool) near Lawrence, Kan. 

 This pool has dried completely for the past three summers, and it is no 

 longer to be taken there. He found it in both the apterous and winged 

 state, living upon the floating mats of Algae and dead Typha stems. It 

 was also found at the Brick Plant pool in all stages in July and August. 



Hibernation. As an adult. 



