October, '12] EwixG: habits of CHEYLETUS 417 



Description of Egg Instar. The egg is white, shiny, oblong-oval. It is aboiit two 

 thirds as broad as long. Generally the eggs are more convex on one side than on the 

 other. During development the buds for the appendages may be seen through the 

 egg-shell. Just before emergence the completely formed larva may easily be seen 

 through the egg's shell. The egg-shell is a thin resistant membrane, which shrivels 

 up after the hatching process. Measurements were made of 7 eggs which 

 gave averages as follows: length, 0.130 mm.; breadth, 0.094 mm. 



Percentage of Larvae Hatching from Eggs Deposited in Captivity. 

 Of the eggs deposited in captivity 66 per cent, hatched. Those that 

 did not hatch did not show developing embryos at any time, but soon 

 began to shrivel and later to contract and dry up. I judged from this 

 that they had not been fertihzed. 



Length of Larval Stadium. Of the 32 larvae which hatched from the 

 eggs deposited I was able to get only 9 to live for any length of time. 

 Yet out of these, 3 passed the larval instar into that of the first nymph. 

 The minimum length of the larval stadium was 6 days, the maximum 

 9 days, the average 7.66 days. 



Description of Larval Instar. Hyahne; in general appearance somewhat like the 

 adult. None of the parts strongly chitinized. Beak very httle chitinized. Palpal 

 claw similar to that of the adult, but without the two tooth-hke tubercles at its base. 

 Inner serr-ida of palpal papilla about four-fifths as long as the outer and without teeth, 

 being simply a large, curved bristle; outer serrula much stouter than inner, number 

 of teeth 6 or 7. Antepenultimate segment as broad as long; femur of palpus but 

 little swollen. Abdomen scarcely as large as cephalothorax. Three pairs of legs 

 present. Measurements were made of three individuals which gave the following 

 averages: length, 0.192mm.; breadth, 0.096mm. 



The larva may at once be distinguished from the nymphs and adult by having only 

 three pairs of legs instead of four as is found in the latter stages. 



Length of First Nymphal Stadium. Two of the three nymphs 

 passed this stadium successfully and became second nymphs. The 

 length of the first nymphal stadium was in one instance 4 days, in the 

 other 5 days. The other first nymph was killed in order to make a 

 permanent mounted specimen of this instar. 



Description of First Nymphal Instar. In general appearances this nymph is similar 

 to the adult, but lacks certain structures while other structures which are found in 

 the adult, in the first nymph have different proportions. Body and appendages, 

 except the beak fleshy, soft, hyaline; tip of beak somewhat chitinized. Beak appar- 

 ently shorter in proportion to the body than in the adult. Palpal claw as in the 

 adult except the two tubercles at its inner side at the base are wanting. Outer 

 serrula of palpal papilla with only 6 or 7 teeth; inner serrula without teeth, being 

 simply a large, stout, cm-ved, tactile seta; cm-ved tactile seta of papilla as in adult. 

 Antepenultimate segment and femur of palpus as in adult. Anterior pair of legs, 

 relativel}^ much shorter in the first nymph than in the adult; tactile bristles of tarsus 

 as long as the segment itself. Last pair of legs extending beyond the tip of the abdo- 

 men by one half their length. Total length of body, including the beak, 0.32mm.; 

 width, 0.16mm. 



