ee. 
—_—"— Se eee eee! sor’ —_— ss —— = 
DESCRIPTION OF GENERA AND SPECIES, 221 
Fematre: Total length, 16 mm.; cephalothorax, 6 mm. long, 4.5 mm. wide; abdomen, 
11 mm. long, 8 mm. wide at the middle, 4 mm. at the base, narrowing to 2 mm. and less 
at the apex. The spider is easily distinguished from its two largest indigenous congeners 
by the peculiar serrated form of the abdomen, and by the brilliant silvery and beautiful 
yellow markings on the basal half of the dorsum. The metallic lustre is caused by masses 
of silvery hairs which closely thatch the cephalothorax and abdomen. This sheen does 
not show in alcohol, and the specimen requires to be dried in order to bring it out in any 
degree. 
CrpHaALorHorax: A long oval; corselet rounded at margins, indented at base, flat, with 
a deep circular fosse; corselet grooves distinct; cephalic suture well marked; ground color 
blackish brown, with a yellow band along the margin of the corselet and a yellowish 
median strip both on corselet and caput; the whole is covered thickly with silvery hairs, 
which give a shining metallic appearance; the caput is quite pointed at the base, flattened 
in front, and much widened at the face, covered also with silvery hairs; sternum shield 
shaped, wide across the front, obtusely triangular at the point; the field dark brown, glossy, 
but covered thickly along the margins with yellowish or silvery white hair; on the anterior 
portion strong black bristles; raised in the middle and in front; with decided sternal cones. 
Labium high, subtriangular; maxille longer than wide, gibbous. 
yrs: Ocular quad on an elevation distinctly depressed in the middle, thus separating 
the front and rear parts into two eminences on which the eyes are seated; the quad much 
longer than wide, decidedly wider behind than in front; eyes not greatly different in size, 
but MF slightly larger, separated by about 1.75 to 2 diameters; MR by 2.5; side eyes on 
high tubercles; MR much larger than MF, the two barely contingent; MF separated from 
SF by a little more than their area, or 1.5 the interval of MF; MR from SR by a space 
much greater than divides MF and SF. Clypeus height 3.5 to 4 diameters MF; front row 
slightly, rear row much procuryed. 
Leas: 1, 2, 4,3; yellow, with broad apical and median dark brown annuli; legs-I, III 
in many specimens darker than II, giving indeed the impression of dark brown legs with 
yellow annuli; freely provided with bristles and long, thin, yellowish spines, and thickly 
covered with silvery white pubescence; palps yellow, with a touch of brown on the ter- 
minal joints, which are tolerably well provided with dark spines and gray: bristles; man- 
dibles conical, dark brown, flecked with yellow, glossy and slightly pubescent. 
AspomEn: Rectangular ovate widest about the middle, narrowing towards the base, 
which is cut squarely across, and narrowing also towards the apex, which terminates in a 
pointed tubercle like a caudal part that extends quite beyond the spinnerets. The dorsum 
rather flat, but the surface much broken; divided into two well marked parts about the 
middle by a thick armor of silvery hairs, with which the base is clothed; at the narrowed 
anterior of the base are two short, distinct, rounded tubercles; the line of separation above 
noted is marked on either side by a similar but smaller tubercle, and there is another in 
the middle of the dividing line; the apical part is divided along its edge on each side into 
two rounded projections or lobes, leaving the apex extended posteriorly from the middle as 
a fifth lobe. The silver armor extends downward along the median line by a narrowing 
band somewhat rounded before it terminates; on either side of this the space is a yellow 
and blackish brown folium, through which branching lines extend towards the apex. The 
venter is beautifully marked by a truncated pyramid of brownish yellow, thickly studded 
with short blackish bristles, and bordered on both sides and behind by a silvery band, the 
posterior part being the widest; between this and the spinnerets is a patch of brown 
flanked on either side by a blackish brown belt, which entirely encompasses the spinnerets, 
at whose base there is a somewhat broken band of yellow; the sides along either flank of 
the ventral folium are black, flecked with brown, in the midst of which are many bristles, 
whose bases are glossy, chitinous, well raised above the surface, and when the shafts are 
broken off add to the glistening appearance of the surface. The epigynum (Figs. 1e-d) has 
a marked resemblance to that of A. argyraspis; the atriolum is rather narrow, the scapus 
rising from its base in a wide yellowish belt, which is indented at the base, and projects at 
the middle into a scapus, which is depressed in the middle but highly arched, and widened 
