378 J. H. Emerton — Spiders of the Family Thornisidce. 



There is little difference between the male and female. The male 

 palpus is slender and the palpal organ small. The tibia is twice as 

 long as wide and has a short process on the outer side. The tarsus 

 is slightly widened across the middle and the palpal organ is oval, 

 about twice as long as wide. The tube is short and curved in a half 

 circle across the end of the bulb. Figs. 4e, \f. 



Medford, Mass. ; Providence, R. I. ; Long Island, N. Y., in N. 

 Pike's collection. The only males I have seen are in the latter 

 collection. 



Tibellus Simou, 1875. 



Cephalothorax longer than wide. Abdomen very long and slender, 

 narrower than the cephalothorax, and straight at the sides. Legs 

 slender with long spines, second pair longest, and the fourth nearly 

 as long as the first. Eyes on the top of the head. Both rows curved 

 and the front row about half as long as the upper. The femur and 

 patella of the female palpi a little thickened. 



Tibellus duttonii Keys. = Thomims dnttmii Hentz. 

 Plate XXXII, figures 5-5c. 



Female, 8 or 10'""' long, the abdomen variable in length and thick- 

 ness. The color is light yellow with light brown markings. The 

 cephalothorax has a middle brown stripe and one on each side, all 

 indistinct. The abdomen has two black spots on the hinder half 

 and a light brown middle spot at the front end extending back half 

 the length of the abdomen and ending in a point, or sometimes 

 continuing the whole length. The abdomen is a little pointed 

 behind and extends back far enough to cover the spinnerets. PI. 

 XXXII, fig. 5. 



The male is a little more slender than the female. The male 

 palpus is bent downward. The patella and tibia are both short and 

 the tibia shorter on the under side than above, so that the tarsus 

 joins it obliquely. Fig. ba. The tibial process is short and blunt. 

 The tube is stout and black and twisted at the tip and has beside it 

 a flat process of about its own length. Fig. 5h. I have not been 

 able to find the spider whose palpus was figured by me on plate 20 

 of the reprint of Hentz's spiders of the United States in 1875. All 

 that I have seen since have the slender portion of the tube longer, 

 as here figured. The epigynum is very far forward and has its 

 opening behind over the transverse fold. Fig. be. 



Massachusetts ; common in the White Mountains and Northern 

 New York. 



