1887.] NATURAL SCIENCES OF PHILADELPHIA. 343 



first moult several day?, and another with young who had just 

 broken the egg. There was no trace of the bifurcated abdomen 

 upon these younglings. 



The spider is of a uniform light green color, about the shade of 

 its cocoon. The cephalothorax is of the same color as the abdomen; 

 in this respect differing from caudata which is black. The head 

 also is not so much elevated as is that of caudata. The adult female 

 is three-eights of an inch in length, and the only specimen of a male 

 obtained is about three-sixteenths of an inch in length, although it 

 is an immature specimen apparently lacking one moult of maturity. 

 The most striking characteristic of the female spider is that the 

 conical prolongation of the abdomen which marks the genus is dis- 

 tinctly cleft at the apex, giving it thus the appearance of the tail of 

 certain fishes and birds, and for this reason it is named CyHophora 

 bifurca. In this respect it decidedly differs from caudata whose 

 apex is without a cleft. On the basal part of the dorsum of the 

 abdomen are four conical jirocesses arranged two on each side 

 symmetrically, the hind pair being the smaller. These processes 

 are soft resembling thus the like cones on the abdomens of the 

 Angulata group of Epeiroids rather than the tough spinous pro- 

 cesses upon Acrosoma and Gaderacanthit. The spinnerets are surroun- 

 ded by a broad white band which extends along the venter as far as the 

 epigynum. The lip is sharply triangular, and the mandibles cut 

 square across. In both these respects the species differs from caudata. 

 The eyes of the front row ai-e about equally separated from each 

 other, although the interval between the mid-fronts is slightly less. 

 The side eyes are barely separated from each other. The male speci- 

 men alluded to above, Dr. McCook could not certainly aflSrm to belong 

 to this spider. It resembles caudata in its general apj^earance, the 

 abdomen lacking the bifurcation which marks the female, and the 

 cephalothorax being of a jet black. 



November 29. 



The President, Dr. Leidy, in the chair. 



Twenty-nine persons present, 

 The following were elected members : 



Messrs Garvin W. Hart, Charles A. Davis, Rev. R. H. Fulton,D.D. 

 and Miss Mary E. Shively. 



Orville A. Derby of Rio Janeiro was elected a correspondent. 

 The following were ordered to be printed : 



