524 | ARANEIDEA. 
Subfam. GASTERACANTHINA. 
The Central-American representatives of this subfamily belong to three genera, 
Gasteracantha, Micrathena, and Tricantha. These are distinguished from the other 
Argyopide by having the spinners placed at the apex of a tubular chitinous sheath. 
The genera at present recognized can be separated by the following characters :— 
GENERA. 
A. Carapace subquadrate; cephalic area raised, forming a transverse 
ridge, usually notched in the middle. Tarsus iv. and apical fourth 
of protarsus set beneath with numerous short, stout, semierect, 
basally compressed, simple spines. . . . . . . . . ~ « . GasrpracantHa, Sund. 
B. Carapace cordiform or oval-elongate; cephalic area not raised to 
form a transverse ridge. Tarsus iv. and apical fourth of protarsus 
set with numerous recumbent, serrate bristles, but without a series 
of semierect spines. 
a. Carapace longer than broad, oval, moderately narrowed in front. 
Eye-groups more separated ; posterior lateral eyes three to four 
diameters distant from the posterior centrals. Abdomen trian- 
gular, broader behind. . . . . . . . . . . . )))6Micrarnena, Sund. 
b, Carapace as broad as, or broader than, long, cordiform, much 
narrowed in front. Eye-groups more closely situated ; posterior 
lateral eyes not more than one and a half diameters distant from 
the posterior centrals. Abdomen triangular, broader in front . MTricanrua, Simon. 
GASTERACANTHA. 
Gasteracantha, Sundevall, Dissert. Consp. Arachn. p. 14 (1883). 
Type G. lata (Walck.). Guadeloupe. 
Carapace scarcely longer than broad; caput raised, forming a transverse ridge; thoracic area excavate. Fovea 
procurved. Mandibles with three teeth on the upper, and four on the lower, margin of the fang-groove. 
Tarsus iv. with 10-15 or more semierect, short, stout spines beneath. Abdomen broad, transverse, and 
covered with a horny integument, having four to six spines. Spinners contained at the end of a 
chitinous tube. 
The species known to me may be separated by the characters given in the Table, but 
it is doubtful if they will prove to be distinct when both sexes of each are available 
for examination. 
a. Abdomen (including spines) about one-fourth broader than long ; spines, 
especially the posterior, more robust, bright orange . . . . . . cancriformis, Linn. ? 
b. Abdomen about one-half broader than long; spines more slender, 
aculeate, black. 2. 2. 2 ew 2 we ew ew ee ww ew ew ew ee) Kochi, Butl. 
