302 | ARANEIDEA. 
runs backwards and outwards, ending in a small spot nearer the hinder extremity of the thorax. There 
are also two small brown spots near together in a transverse row on the median line halfway between 
the eyes and the thoracic indentation, and another on each side just behind the large brown patch ; and 
the anterior corners of the caput are deep brown. 
Eyes normal. The central quadrangle is equal in length and breadth, though the anterior side is the longest ; 
its anterior eyes are slightly larger than the posterior. The interval between these posterior eyes is 
equal to nearly a diameter and a half, that of the anterior to nearly two diameters. In an immature 
specimen the length of the anterior and posterior sides of the quadrangle appeared to be equal or very 
nearly so. The height of the clypeus is less than half that of the facial space. 
Legs moderate in length and strength, ?1, 2, 4, 3 (in the only adult example seen both legs of the 4th pair 
were wanting). They are yellow in colour, annulated and marked with black-brown, and furnished, but 
not conspicuously, with short spines, hairs, and bristles. 
Falces strong, deep brown, with a large curved yellow patch clothed with white hairs at the base in front. 
Maxille and labium normal in form, dark brown, yellow at the extremity. 
Sternum cream-yellow, with black-brown irregular lateral margins. 
Abdomen subtriangular, broad in front, obtusely pointed behind, slightly prominent at the shoulders, like some 
examples of Epeira diademata, Clk. Colour cream-white; fore extremity and lateral margins black- 
brown, zigzag or irregularly indented ; on the middle of the hinder half of the upperside are two deeply 
indented longitudinal converging lines, representing all that is left of the ordinary Epeirid foliated central 
marking. The posterior extremity of the marking is more or less black, and has on it two pairs of round 
cream-white spots in longitudinal series. Underside more or less suffused with blackish-brown, with 
a somewhat diamond-shaped central white patch. Genital aperture of a transverse-oval form, with a 
triangular process drawn out and directed forwards; this process is crossed with deep transverse rugs 
or indentations and its prolonged extremity has an articulated appearance. 
Hab. Costa Rica (Sarg). 
This spider is allied to Hpeira anastera, Walck., but is, I think, distinct from all the 
varieties of that variable species. 
ACROSOMA, Perty. 
Acrosoma bimucronatum, sp. n. 
Adult female, length very nearly 3 lines (6 millim.). 
Cephalothorax of normal form ; colour yellow-brown, the greater part of the sides of the thorax dark reddish- 
brown. 
Eyes in normal position. Central quadrangle forming a square, whose anterior side is shorter than the posterior ; 
the hind-central eyes are much the largest, double the size of the fore-centrals, which are cluse to the lower 
margin of the clypeus. 
Legs short, 4, 1, 2, 3, not very strong; the second pair nearly equal to the first. They are yellow-brown in 
colour, furnished with hairs and bristles, scarcely spines, properly so-called. The femora of the first and 
second pairs are furnished beneath with somewhat tuberculous-looking transverse ridges or eminences. 
Falces strong, very roundly prominent at their base in front, where they are furnished with numerous strong 
bristly hairs, especially near their fore extremity on the inner side. Colour dark reddish-yellow-brown. 
Maxille, labium, and sternum dark brown ; the maxille have a pale border on the inner side, and the labium a 
pale apex. 
Abdomen large, corneous, truncate before, the corners slightly prominent, double as wide behind as in front - 
upper surface flattish, each hind corner produced into a strong, tapering, sharp-pointed spur, whose 
length is equal to the length of the abdomen, and its base as broad as the interval between the bases of 
the two spurs. Colour pale orange-yellow, deepening into red-brown at the extremity of the spurs. 
The upperside is marked with numerous small sigilliform deep red-brown and blackish spots in the usual 
position. The abdomen is, as usual, prominent below, the spinners occupying a circular cavity with a 
deep red-brown corneous rim at the most prominent point ; between the spinners and the bases of the 
