2 28 Annals Entomological Society of America [Vol.1, 



to moulting or breeding time, as I supposed at first. The bur- 

 rows enlarge considerably below the upper half, and commonly 

 become nearly horizontal below, with rough, irregular, usually 

 unlined walls, except at egg-laying times, — nests with cocoons 

 usually being well-lined. The "cocoon" is fastened to the roof 

 of the cavern. Egg-laying is probably in early summer, but I 

 have no exact data yet as to the month. Numerous cocoons, 

 found in September and October, contained the exuviae of the 

 young's first moult; but the young were gone in all cases. Over 

 fifty of these exuviae were counted from one cocoon. Cast skins 

 of the adults are commonly found in both occupied and deserted 

 burrows, in the Autumn. 



Mating time is in the Autumn, when the males may frequently 

 be found walking about on the surface of the ground. Oct. 30th, 

 a pair were taken from one burrow. The female was met with 

 several centimeters up the tunnel, she being more aggressive 

 than usual. The male was down below, and, unlooked for and 

 unexpected, was injured in one palpus and one leg as I was roughly 

 following the long burrow to its end; but the two were brought 

 alive into the laboratory and put into a spacious cage together. 

 The next day the male was found partially wrapped in silk, with 

 the female standing over his remains, still feeding. Later she 

 dug something of a cavity in the soil of the cage and lined the 

 entrance and vicinity with considerable silk. One male was 

 found alone in a well constructed, rather long burrow. It may 

 not have dug the cavity itself, however, as it may have merely 

 appropriated an abandoned one. Males have been found under 

 rocks and planks. 



Brachythele is common on Jasper Ridge, mentioned above 

 in connection with Eurypelma. Mr. Derby and myself being 

 surprised to find a Brachythele at the bottom of a few of the bur- 

 rows amidst the colony of Eurypelma. Similar soil, etc., only 

 a stone's throw away, contained many Brachytheles, but no 

 Eurypelmas. Hence we had a good chance to compare the nest- 

 ing habits of the two very different species. In fact, we looked 

 in vain for some external evidence sufficient to identify with cer- 

 tainty the genus of the occupant of the burrow. Altho the bur- 

 rows of Brachythele undoubtedly average more in length and 

 are not so apt to be close to rocks, so much variation exists as to 

 the depth, various diameters, shape, directions, web-lining, proxi- 

 mity to rocks, etc., that we found it impossible really to know 



