1879.] NATURAL SCIENCES OF PHILADELPHIA. 151 



gradually contracted and withdrawn within the black corneous 

 bulb, which was meanwhile pressed eagerly against the epigynum. 

 A small elbow or projection upon the upper part of the bulb 

 seemed to press within the spermatheca of the epigynum. The 

 two bulbs were laid simultaneously upon the tubes of the sperma- 

 thecse, but the inflated sac appeared in but one bulb at a time ; 

 the latter action alternated in the bulb. There was a prolonged 

 squeezing motion of the bulbs, as though pressing into the sper- 

 mathecae, and at times a corresponding motion in the abdomen 

 of the female, especially at the apex. With this exception the 

 female remained motionless during the whole period of copulation. 

 After application as above the male bulb was slowly, for the most 

 part, but sometimes rapidly, raised, bent upward, and apparently 

 clasped upon the falces or lower margin of the face, which parts 

 of course were upward. Three or four movements back and forth 

 in this clinched position followed, when the series of motions 

 above described was repeated. 



In the meanwhile the other bulb remained upon the other tube 

 until the first bulb began to descend, when it in turn was elevated, 

 and the same motion made. As the bulb descended the sac began 

 to inflate and issue. The above is the process as it was quite 

 regularly repeated. Sometimes, however, both bulbs were clinched 

 upon the falces at the same time; sometimes the movements of 

 the bulb were more rapid than at others. The bulbs had the 

 appearance of having been moistened by some secretion, present- 

 ing the peculiar gloss which a colorless liquid gives to a black 

 surface, but he could see no secretion otherwise, although he was 

 able at any time to use his pocket lens with the exercise of a little 

 care. 



At twenty minutes before 6 six o'clock he was compelled to 

 leave, at which time the pair had been in embrace one hour and 

 forty-nine minutes. At six o'clock twenty-eightminutes he returned, 

 and found the pair in precisel}' the same positions. He remained 

 five minutes, and then left an intelligent young man at the post, 

 with full instructions as to points of observation. He reported 

 that at thirteen and a half minutes to seven P. M. the pair parted 

 very suddenly. The male ran downward to a portion in the lower 

 margin of the dome pursued by the female, who stopped suddenly 

 just above and turned back to the central point in the summit of 

 the dome. Shortly after receiving this report Mr. McCook visited 

 the nest and found the female suspended motionless in this posi- 

 tion and the male at the point to which he had fled, feeding upon a 

 small fly. The next morning at seven o'clock the female was in the 

 same position, and the male had disappeared. He attempted to 

 capture the female, but she ran among the boards and escaped. 

 The pair had thus been in union two hours and fifty-five and a 

 half minutes. 



During this period they were separated a number of times. 



