66 PROCEEDINGS OF THE ACADEMY OF [Jan., 



attachment of the threads, thus laying down looped threads. As she 

 did so she rotated her body slowly, keeping the tips of her palpi pressed 

 against the portion of the margin opposite the one to which she applied 

 her spinnerets. So she formed a narrow marginal wall, low but quite 

 visible to the naked eye, made entirely of looped threads. This was 

 finished at S.35. Then she stood so across the cocoon base that her 

 palpi touched the wall in front and her spinnerets the wall behind, and 

 oviposited upon the centre of the base. From her genital aperture 

 fell a large ch'op of viscid fluid, its upper surface remaining adherent to 

 her genitalia, and the yellowish ova dropped into it one by one. The 

 oviposit'on lasted from 8.36 to 8.41, when she tore herself loose from 

 the viscid drop and started to spin the cover of the cocoon. She spun 

 over the egg mass uninterruptedly from 8.41 to 8.59, forming a dense 

 covering and battening the silken wall down at the same time. From 

 8.59 to 9.01 she occupied herself with loosening the cocoon from the 

 glass floor of the cage, doing so by seizing with her chelicera and pulling 

 first one part of the edge of the base, then another, bracing her legs 

 firmly against the ground, until she had completely loosened it. She 

 then held it a moment attached to her spinnerets, then from 9.02 to 

 9.24 held it below her cephalothorax with her third pair of legs, revolv- 

 ing it in this position with her palpi, and spun upon its surface with 

 abdomen flexed vertically downward. Thus was formed a perfect 

 globular cocoon, white in color. 



(2) 9 No. 228 was observed at the close of the cocooning, which was 

 like that of the preceding case. 



(3) 9 No. 229 did not spin the bas;^ of her cocoon directly upon 

 the floor of the cage, but upon a scaffolding of threads inclined at a 

 slight angle to the floor and joined to the wall. From 11.03 to 11.17 

 A.M. she was occupied in spinning the marginal wall, from 11.18 to 

 11.22^ in the oviposition, from 11.23 to 11.58 in making the covering 

 (in the first part of which she elevated her spinnerets and did not 

 brush them, thus preventing them from adhering to the viscid drop), 

 from 11.58 to 12.02^ in tearing the cocoon loose, and from 12.05 ta 

 12.30 in spinning upon the cocoon while h^ld beneath her body. 



These three were the only normal cocoon-makings observed. This 

 species is peculiar in sometimes making tlie base of the cocoon without 

 a preliminary scaffolding. 



All the other cases resulted disastrously, due either to the spinnerets 

 of the mother becoming clogged with the viscid suljstance surrounding 

 the eggs, or, in most of the cases, to her maldng the mistake, when 

 tearing the cocoon loose from the flo(;r, of tearing the cover from 



