270 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



No. 116. Pachygnatha Dorothea, new species. Plate XXVI, Figs. 3, 4. 



Female: Total length, 4.3 mm.; cephalothorax, 2 mm. long, 1.5 mm. wide; abdomen, 

 2 mm. long, 1.3 mm. wide. Tlie single specimen in hand is much dried up, and the pro- 

 portion and markings of the abdomen are indistinct. 



Ceph.\lothor.\x : Ovate, truncated behind ; skin glossy, color brown ; fosse a low 

 circular pit ; grooves sufficiently distinct ; suture well marked ; caput somewhat elevated 

 above the corselet level ; the eye space not elevated. Sternum uniform reddish brown, 

 though somewhat lighter in the middle. The surface punctured. 



Eves : Ocular quad (3a), somewhat wider behind ; the rear width about equal to the 

 length; eyes of the group nearly equal in size; MF divided by about 1.3 diameter; MR by 

 2 diameters. MF separated from SF by about twice the intervening space of MF. The 

 front eye row slightly recurved ; the longer rear row procurved. 



Legs : Uniform yellow color, thickly covered with long, delicate bristles. The man- 

 dibles are yellowish brown, heavily clothed with long bristles at tlie edges. The mandibles, 

 viewed from in front, show on the upper exterior surface about one-third the distance 

 from the apex, a decided hump, so that the outline presents an obtuse angle (3a). This 

 feature distinguishes the species from others of the genus. The mandibles are widely 

 separated at the apex ; the superior furrow row has about four teeth. 



Abdomen : The abdomen is ovate, the specimen too much shriveled to give the dorsal 

 folium with accuracy. The epigynuni is located near the middle of the venter, and is a 

 decided arch, without scapus. The surface is extremely hairy. 



Male: (Fig. 4.) 4 mm. long; the cephalothorax glossy brown, but showing a lighter 

 or yellowish shade on either side of the median line. The eyes are substantially as in the 

 female ; but those of the ocular quad somewhat more widely separated. Tlie mandibles 

 (4a) are yellowish brown; widel)' separated at the tips; nearly straight, or with but a .slight 

 concavity on the outer margin. The fang (4a) has a slight tooth on the interior, at about 

 the middle point. The digital joint of the palp (4b) is long ; the radial joint slightly 

 longer than the cubital. 



Distribution : The only two specimens of this genus which I possess were found in 

 the neighborhood of Philadelphia. I have named it in honor of Mrs. Dorothea Marx, the 

 devoted and helpful wife of Dr. George Marx, of Washington. 



No. 117. Pachygnatha tristriata C. Kocn. Plate XXVI, Fig. 6; Plate XXVIII, 1. 



1845. Pachygnatha tristriata, C. Koch . Die Arach., xii., p. 145, Fig. 1046, male. 

 1883. Pachygnatha tristriala,K^YSEiii.iyG. Neue Spinn. Amer., v., p. 656; xxi., 8. 

 1889. Pachygnatha trutriata, Marx . . Catalogue, p. 553. 



Female : Total length, 7 mm.; cephalothorax, 2.5 mm. long, 1.5 mm. wide ; the abdomen, 

 3.5 mm. long, 2.3 mm. wide, narrowing at the apex to 1 mm.; length of mandible, 1.2 mm. 



Cephalothorax : Oval ; dark brown, with a glossy, leathery ajipearance ; corselet 

 groove distinct ; cephalic suture well marked ; fosse a narrow circular pit ; color, a warm 

 yellow to dark brown, with a median longitudinal band of brown, and ligliter shade on 

 either side thereof. Sternum squarely truncate at the base, raised in the middle ; color 

 brown, with a lighter median band ; covered with short, soft pubescence. The labium is 

 yellowish, large, and wide at the base, obtusely triangular, dark brown in color ; the 

 maxillre yellowish brown, subcylindrical, much longer than wide. 



Eyes: The ocular quad upon a high, squarish eminence, projecting forward and upward 

 from the face ; narrowest in front ; the rear widtli being greater than the length ; the eyes 

 on black bases, not greatly differing in size, but MF somewhat greater ; the side eyes are 

 upon tubercles, and propinquate ; SR smaller ; SF separated from MF by a space about 1.4 

 to 1.3 greater than the area, or at least twice the intervening space of MF ; the distiince 

 between SR and IMR is somewhat greater than the above. The clypeus is extremely high, 

 the margin thereof being removed from MF by twice or more the area of IMF. The front 



