1980] 
Eberhard — Bo las Spider 
147 
First leg with metatarsus much thinner than tibia and slightly 
curved, median claws large and strongly curved. 
Abdomen broad and subtriangular as seen from above, shallowly 
emarginate anteriorly and broadly rounded on sides, presenting a 
pair of clearly defined but not large tubercles slightly posterior and 
median to the shoulder humps. Abdomen overlapping carapace 
about to the horns, highest just anterior to the tubercles and declining 
steeply behind, with the caudal portion rounded. Abdomen hairless 
except for ventral surface anterior to spinnerets. Deepness of 
wrinkles along sides related to how recently spider oviposited. 
Spinnerets with apical segments short and subconical. The epi- 
gynum is illustrated in Fig. 4. 
Male: Total length of holotype from Lago Calima, Valle, Colombia is 
1.81; carapace .87 long; abdomen .91 long and 1.35 wide. 
Coloration of carapace brown (reddish orange) with longitudinal 
white stripe forming dorsal triangle, eyes lighter. Abdomen white 
with scattered small grey blotches at anterior dorsal margin. Three 
pairs of large sclerotized depressions present, and tubercles posterior 
to first pair and separated slightly more than the depressions. 
The palpus is illustrated in Figs. 7-9. 
Type Localities: Female holotype from field on Melendez campus of 
Universidad del Valle at southern edge of Cali, Colombia. Male 
holotype from field at eastern edge of Lago Calima, near Darien, 
Valle, Colombia. 
Distribution: Western Colombia in Departamento Valle del Cauca. 
1000-1400m el. in western range of Andres. 
Other Records: mature female, other mature males, several juveniles 
from type locality of male holotype. 
Natural History and Behavior 
Web construction and prey capture 
The form of the bolas and its construction were basically the same 
in M. dizzydeani as those of M. cornigera as described by Hutchinson 
(1903) and Gertsch (1947). A number of details were different, 
however, perhaps due to species differences, and are described below. 
As the spider moved back and forth on the horizontal (trapeze) line 
prior to starting a bolas (Fig. 10a), she did not reinforce the line, but 
rather repeatedly broke it, and reeled up the old line as she payed out 
a new one behind, her body thus forming a bridge between the two 
lines. She often descended somewhat as she broke the line, and waved 
