562 PROCEEDINGS OF THE ACADEMY OF [DeC, 



and of interruption of the cocooning process by such mating. Only 

 an hour and a quarter after the last copulation she oviposited. During 

 the cocooning she was aggressive, raising her fore-legs, but c? B pressed 

 them down by rapid tapping and mounted over her head; the mating 

 was forced upon her against her maternal instinct. 



Prosthesima atra (Hentz). 



One male and four females were caught 7 August and placed in a 

 large dish, all unable to walk on the vertical glass side. On 9 August 

 the male was seen in mating attitute, but without palpal insertion, for 

 a quarter of an hour; this was at 5.20 P.M., and at 6.55 he was again 

 motionless upon a female, but without insertion of the palpi. Could it 

 have been that he was waiting for her to moult? On 15 August a 

 copulation was observed, the attitude as in Geotrecha; the pair was 

 first seen at 8.40 P.M. (they were not in copula a quarter of an hour 

 before), and during the succeeding 19 minutes he inserted his left 

 palpus 4 times and his right 3 times, each insertion lasting from 1 to 2 

 minutes. Another copulation was seen on 20 August at noon. 



Misumena aleatoria (Hentz). 



The male of this Thomisid is many times smaller than the female. 

 A pair were placed together in a cage on 27 August. In the copulation 

 both palpi are inserted simultaneously, and the male is placed upon 

 the ventral surface of the abdomen of the female with his head pointed 

 in the same direction as hers; the ventral surfaces of the two are 

 apposed. The male, after discharge of the sperm, may remain upon 

 the female's venter or may climb to her dorsum. He continues to 

 hold to the female for astonishingly long periods, for he is so small and 

 nimble that she is unable to displace him. Thus at one time he 

 remained upon her for 22 hours, even though I disturbed them by 

 removal to a bottle, and I found it difficult to push him off with a 

 pin ; at another time he remained continuously upon her from 4.57 P.M., 

 30 August, until 7.30 A. M., 1 September, when he left her, but regained 

 her at 9 A.M. and remained upon her until the following morning, when 

 she was found dead. Even her walking around the cage did not seem 

 to disturb him. Palpal insertions occupied only a small part of these 

 periods. 



Xysticus nervosus Banks. 



Two adult males and an immature female were placed in one cage 

 on 5 September. She repulsed their advances, and after moulting 

 on 11 September, was placed again with the males. One male found 

 and embraced her, then the other drove him off, or the first left the 



