192 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
hairs. Sternum cordate, one-half longer than broad, with sternal cones, color yellow, 
numerous bristlelike hairs; labium dark brown at the base; maxille gibbous, longer than 
broad, bluntly triangular at the tips, which are inclined inward. 
Eyres: Ocular quad elevated; length somewhat greater than width, rear slightly wider 
than front; MF separated by about one diameter; MR about 1.5 their diameter; side eyes 
on black tubercles; barely contingent; SF somewhat larger than SR; SF removed from MF 
by about 2.5 the area of the latter, or at least five or six times the intervening space of 
same; SR removed from MR by a slightly greater distance than separates SF and MF; 
clypeus height about two diameters MF, the base of the rounded eminence coming close to 
the margin; the front row is scarcely curved, the eyes aligned; the rear row is a little 
longer and slightly procurved; the forehead is high and well rounded. 
Leas: 1, 4-2, 3; rather short, but drawn too short and pointed in the figure; stout; 
color dull (greenish) yellow, except the feet, which are brown; well provided with 
pubescence and whitish yellow bristles, somewhat sparingly with rather short yellowish 
brown spines; palps armed and colored as the legs; mandibles strong, conical, yellow, with 
slight brown at the tips. ; 
Aspomen: A long triangular ovate, widest at the summit of the base; the front raised 
high above the cephalothorax; the dorsum not arched, but rather flat or curved inward to 
the apex, which terminates in a rounded cone or caudal part, although Cambridge describes 
this part as “not in a caudal form.” Strong conical shoulder humps, which terminate in 
sharp brown points, mark the base; the folium is not distinct; the general field is yellow, 
reticulated, with brownish margins, from which issue longitudinal lines to the apex, which 
is touched with blackish brown, and covered with a tuft of yellowish hairs; the spinnerets 
are placed far underneath the projecting apex of the abdomen, brown in color, surrounded 
by a base of yellowish spots; the venter is brown, with marginal ribbons of yellow merg- 
ing into the sides, which are brown, with yellowish lateral patches; the epigynum presents 
a subtriangular cup shaped scapus, very wide at the base, rounded at the top, brown and 
chitinous; the basal part thereof is an irregular quadrilateral, somewhat wrinkled; smooth 
and hollowed on the lower part, like the scapus. Cambridge’s drawings of this seem very 
defective, probably from an immature species. 
DistrreuTIon: Biscayne Bay; two specimens, female. (Marx Collection.) Cambridge 
describes it from Panama. The species is thus probably distributed along the coasts of 
Central and subtropical North America. 
Genus MARXIA, new. 
I have thought it necessary to make a new genus to receive the species originally 
described by Walckenaer as Plectana ‘stellata. Subsequent writers haye relegated this 
species to Epeira, on the grounds of the strong likeness in the mouth parts, the general 
grouping of the eyes, and form of the legs. The peculiar tuberculated condition of the 
abdomen has not been regarded by these authors as of general value. To me it seems 
unreasonable that an organ of such prominence, which contains the vital organs, and 
especially the spinning apparatus, by whose functions the animal is most sharply differen- 
tiated from members of its class, and, indeed, all other animals, should count for nothing 
in classification. It has been urged that the abdomen, by its softer covering, is more 
plastic, and therefore presumably more liable to changes, through environment and other 
influences, than the harder cephalothorax. Yet I haye not found that, in point of fact, 
the abdomen is less persistent in its peculiar forms, as characteristic of various species, 
than other parts. . 
I have therefore considered that a peculiarity so striking as that shown in the tuber- 
culated margins of the dorsal field, if not sufficient ground in itself for separating these 
specimens from Epeira, at least should be considered as one distinctive feature. In addi- 
tion, however, Marxia is well separated from Epeira by the form of the cephalothorax, 
which is strongly elevated at the caput above the corselet. In Epeira, on the contrary, the 
head is on a level with the crest of the corselet, or more frequently depressed therefrom. 
