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NEW YORK STATE MUSEUM 



to learn how this airy chamber or vivarium was constructed. On the 

 ground, as before stated, the insects appear nearly helpless. When 

 suspended from the branches they could easily pull leaves, etc., 

 together, but they appear to have no means of fastening them in 

 place. This interesting habit does not seem to be common to any 

 American species yet observed. 



A Remarkable Organ. 

 Arising between the large appendages of the tenth abdominal 

 segment of the male there is a most remarkable median organ; it is a long, 

 slender filament of chitine coiled up like the proboscis of a butterfly 

 ■(PI. iii, fig. 14 f). It is also represented partly extended in figure 

 15 f. When stretched out it would quickly spring back to its original 

 position upon being released. This was observed upon males that had 

 been dead some forty hours and also upon alcoholic specimens. The 

 insect cau uncoil this filament. It appears like the rudiment of a once 

 important organ. 



Egg-laying Habits. 



The perfect state lasts a number of days and possibly a month or 

 more. Owing to their requiring living food, it was difficult to keep the 

 insects alive when in confinement. A female of B. pilicornis Westw 

 was kept five days; during that period she killed eight house-flies, and 

 there were times when she would have been glad of more. The first 

 day of confinement she laid one egg and several each day thereafter; 

 before dying, thirty were deposited. This species was less abundant 

 at Ithaca and appeared much less vigorous than B. strigosus. Several 

 examples of B. strigosus with well-distended abdomens were dissected; 

 they were found to contain fourteen, sixteen, and nineteen eggs, 

 respectively, yet the abdomens were apparently as large as that of 

 B. pilicornis, which laid thirty eggs. From the above it would seem 

 that the eggs develop and are produced a few at a time during the 

 greater part of the adult existence. These insects die very soon if 

 deprived of food, most of them living but a day after capture unless 

 well supplied with small insects. So far as observed, ovipo^ition con- 

 sists simply of extruding the egg and allowing it to drop at random. 

 It has a hard f-hell and a tough inner membrane, differing in this 

 respect from that of Panorpa. 



The egg. — Subcuboidal; long diameter, .8125 mm.: short diameter, 

 .6875 mm. Color, dark brown. Shell hard, tuberculate. It appears 

 like the "frass" of a caterpillar (PI. iv., fig. 9). 



