CHAMBERLIN: ARACHXIDA of PERUVIAN ISLANDS. 41 
affinities of this form. It is separated from L. accepia of the mainland 
chieflv becau.se of the difference in e\e relations noted above. 
ARGIOPIDAE. 
Tetragnatha aptans, sp. nov. 
PI. 4 figs. 7 and ,S. 
Female. — Carapace fulvous or with a median brown stripe which is 
geminate on head and a brown stripe along each lateral margin. 
Sternum dusky or black, sometimes paler at middle. Labrum black. 
Legs with fulvous background; femur, tibia and metatarsus typically 
with a black annulus at distal end, the femur and tibia when in full 
color also dusky elsewhere but having a distinct light ring adjacent 
to the distal black one and the metatarsus darkened along middle section. 
Abdomen with the usual elongate folium above; ventrally a median 
longitudinal black band bordered on each .side by a narrower orange or 
rufous strii)e. 
Abdomen widening conspicuously from caudal end forward to in 
front of middle, from where it again narrows; anteriorly protruding 
forward and there weakh- bigibbous. 
Po.sterior row of exes moderately recurved; median ej-es somewhat 
more than their diameter apart, once and a half or more their diameter 
from the lateral on each side. Po.sterior lateral eye larger than the 
anterior, the eyes separated by less than the diameter of the posterior 
one. Area of median eyes a little wider behind than in front and than 
the length. Anterior median eyes farther from the posterior medians 
than the laterals on each side are from each other. Anterior median 
eyes their diameter apart and about twice as far from the laterals. 
Chelicerae more than eight tenths (seventeen twentieths) as long as 
cephalothorax. Chelicerae with nine teeth along lower margin of which 
the second is reduced, with the intervals between it and the first and 
third respectively wider than other intervals; first tooth .somewhat 
.stouter than third, the third and three following subequal, the remain- 
ing ones moderately decreasing. Upper margin also with nine teeth, 
the intervals between first and .second largest, that between .second and 
third a little less, the other .seven clo.se together; first three teeth large, 
the others gradually decreasing caudad. At distal end of chelicera on 
ventral side a short process of triangular outline. Claws of chelicera 
