PHALANGES OF THE UNITED STATES. 21 



more pronounced than in P. dorsatum, distally pubescent. Segmenta- 

 tion of the abdominal scutum pretty well marked, especially poste- 

 riorly. Ventral surface light brown, with the abdominal segments 

 very distinct, without tubercles, save a few anteriorly. Coxce of 

 the same color as the belly, but covered with numerous close tuber- 

 cles, tipped with white. Trochanters, light brown. ie(/s very slender, 

 light brown, with black aunuli at the distal femoral and tibial joints, 

 which in some specimens involve the whole article, furnished with 

 numerous small, black, spinous tubercles. Penis very slender, not 

 flattened, distally bent at right angles to itself, into a moderately 

 short, very sharp point. 



Female. — With the general characters of the male, but much 

 larger, and the palpi much shorter. The dorsal stripe not nearly so 

 pronounced as in the male, and very often interrupted posteriorly. 

 The legs not so dark. 



Length of Body, $,0.4; $, 0.25. Length of Legs, $, (1) 1.7, (2) 

 3.2, (5)1.6, (4) 2.3; ^, (1) 1.7, (2) 3.2, (3) 1.6, (4) 2.1. 



Remarks. This species is closely related to P. do7'- 

 satmn, the principal characters separating the two are to 

 be found in the differences in coloration of the dorsum 

 and legs, the trochanter not being black in P. vittatmn, 

 and the much greater hardness and roughness of the 

 upper surface of the southern species. 



The color varies considerably. Some two or three 

 specimens are nearly white. 



This species was originally described by Mr. Say as an 

 inhabitant of the Southern States, and may be looked 

 upon as the southern representative of its nearest ally, 

 P. dorsatum, of which I have never seen any specimens 

 from farther south than Washington City. Most of the 

 specimens of P. vittatum, which have come under my 

 notice, were collected by Dr. G. Lincecum in Texas, 

 where it appears to be abundant. Like many other ani- 

 mals of the Neo-tropical fauna of i^orth America, its 

 range extends up into Nebraska, for I have a number of 

 specimens collected last summer by Prof. F. V. Hayden, 

 during his geological explorations of that State. 



