Supplement to the Neiv England Spiders. 181 



The markings of the abdomen are distinct at the anterior end 

 and also over the spinnerets, while in the middle they consist of 

 small and indistinct spots in irregular transverse rows extending 

 down the sides. At the anterior end is a bright white spot with 

 a larger black spot on each side sharply defined toward the middle 

 line, and irregular and indistinct at the sides. At the hinder end 

 over the spinnerets is a white spot with short black stripes at the 

 sides. On each side of the abdomen is a short, dark, vertical stripe 

 that in some individuals is deep black. 



In the male the markings of the abdomen unite into a more 

 distinct middle light stripe, bordered b}' two dark ones, but the 

 white spots at the ends are distinct as in the female. 



The epigynum is small and rounded behind with two openings 

 twice their diameter apart. The skin is so transparent that the 

 tubes of the epigynum are seen through it and obscure the openings. 



At the end of the palpal organ is a long thin appendage, widened 

 and twisted at the end, partly enclosing and supporting the tube. 

 PI. 1, fig. 6a. 



Found at New Haven, Conn., Jaffrey, N. H., and by Dr. Fox at 

 Hollis, N. H. 



Latrodectus mactans, Fabr. 

 Theridion verecundum, Hentz. 



This is the largest and most conspicuous species of the family. 

 The abdomen is round, sometimes a centimeter in diameter, and the 

 whole body is deep black except a bright red spot under the ab- 

 domen and one or a row of red spots on the upper side. In alcohol 

 the spots fade to white or yellow: In young individuals there is 

 a white line around the front of the abdomen and three rows of 

 spots partly white and partly red along the back, and the legs are 

 brown in the middle of the joints and black at the ends. The 

 adult males are marked much like the young with the lateral spots 

 elongated and with a red line in the middle of each. The males 

 are much smaller than the females, some of them only three or 

 four millimeters long but with long legs. The lateral eyes, which 

 in most Therididae are close together, are in Latrodectus as far 

 apart as they are from the middle eyes. The epigynum is of the 

 usual Theridion pattern with a single, wide, oval opening partly 

 divided on the front edge. The palpal organ has a very large and 

 long tube coiled in two flat turns across the end of the bull). In 

 alcohol this tube often becomes displaced and coils around the bulb 

 in any direction. 



