DESCRIPTION OF GENERA AND SPECIES. 259 



powerful than in the female. The abdomen is cylindrical, or subcylindrical, elongated, 

 decidedly longer than wide. The legs are long, attenuated, sparsely clothed with long, 

 aculeate spines, and more abundantly with bristles and hairs. The number of rows of spines 

 down the tibia is ordinarily about three; npon the metatarsus from two to three; upon the 

 femora, ordinarily from six to eight. The orbicular snare is commonly hung horizontally, 

 or at an angle more or less inclined. It is frequently found near or immediately over 

 water, as the species afJect humid places and the banks of streams. While seated upon its 

 snare the four front legs are usually stretched out straight before the face. 



No. 106. Tetragnatha extensa (Linnjeus). Plate XXV, Figs. 3, 4, 5. 



1758. Aranea extensa,^ Linn.eus .... Syst. Nat, Ed. x., i., p. 621. 



1763. Aranea Solandri, Scopoli .... Entomologia Carniolicse, p. 397. 



1763. Aranea Mouffeti, Scopoli .... Ibid., p. 398. 



1805. Tetragnatha extensa, Walckenaer, Tabl. d. Aran., p. 68. 



1837. Tetragnatha ohtusa, C. Koch . . Uebers. d. Arachn. Syst., i., p. 5. 



1842. Tetragnatha versicolor, Walck. . . Ins. Apt., ii., p. 215 ; Abbot, G. S., No. 466. 



1861. Tetragnatha extensa, Westkixg . . Aranese SvecicK, p. 84. 



1864. Tetragnatha extensa, Blackwall . Sp. G. B. & I., ii., p. 337, xxviii., 265. 



1866. Tetragnatha extensa, IMexge . . . Preuss. Spinn., i., p. 90, pi. 15, tab. 26. 



1866. Tetragnatha ohtusa, Menge . . . Ibid., p. 93, pi. 15, tab. 27. 



1870. Tetragnatha externa, Thorell . . Synonyms European Spiders. 



1877. Tetragnatha externa, Thorell . . Aranese Colorado,^ Bull. U. S. Geol. Survey.* 



1884. Tetragnatha extensa, Emerton . . N. E. Ep., 333, pi. 39, Figs. 9, 10. 



1889. Tetragnatha extensa, McCooK . . Amer. Spiders and their Spinningwork. 



Female : Total length, 8.5 mm. ; abdomen, 6.3 mm. long ; across base, 3 mm. wide ; 

 across apex, 1.5 mm. wide ; cephalothorax, 2.5 mm. long by 2 mm. wide. The general 

 colors of the fore part are yellow and yellowish brown, and of the abdomen various shades 

 of yellow and greenish. While young, often a uniform light green (Fig. 5b). 



Cephalothorax : A long oval, truncated and indented behind, widest at the middle, 

 flattened at the top ; dorsal fosse deep ; corselet grooves sufficiently distinct ; cephalic suture 

 distinct; the head elevated above the corselet level; the caput wide, the projecting part or 

 head of nearly equal width to the face ; color, a warm yellow, with brown markings on 

 sides of caput and margins of corselet ; skin glossy, pubescence scant. Sternum (od) a long 

 shield shape, tapering to a point, high in the middle, slightly pubescent ; color, a broad, 

 yellow median band, with blackish or dark brown margins ; labium subtriangular, relatively 

 shorter than in T. grallator ; maxilhe concave on the outer edges, of nearly equal width 

 throughout, but widest at the tips. 



Eves: (3, 3b.) MF on a central prominence; the MR not thus elevated; ocular quad 

 narrowest in front, the rear wide as, or wider, than the sides. MF smaller than BIR, 

 separated by 1.5 to 2 diameters, MR separated by 2 to 2.5 diameters. Of the side eyes 

 SR are the larger ; they are separated from one another by about two-thirds the space 

 which divides MF from MR. MF are sejiarated from SF by about 1.25 their area, and 

 from the margin of the clypeus by about 2.5 diameters. The front row slightly recurved, 

 the rear row slightly procurved, almost aligned. The distance between MR and SR is 

 about equal to the space between the two MR. 



Legs: 1, 2, 4, 3; first pair at least eight times length of cephalothorax; of uniform 

 yellow color, except slightly darker annuli at the joints, feebly armed with pubescence, 

 bristles, and a few blackish spines. The mandibles {3a, 3b) about seven-tenths the length 



' A complete synonymicon would fill several pages ; 1 give but a few of the more important synonyms. 

 ' Professor Thorell appears to me in this report to have confounded variations of this species with 

 T. elongata (graUator). 



