1896. ] SPIDERS FROM THE LOWER AMAZONS, 733 
ACANTHODON SANTAREMIA, n. sp. (Plate XXXIV. fig. 13.) 
9. Hab. Santarem, Lower Amazons. 16 mm. long. Type in 
coll. Brit. Mus. Nat. Hist. 
9° .— Colour. Carapace dull orange-brown ; mandibles the same, 
darker towards apex. Sternum and legs also dull orange-brown ; 
tarsi slightly darker. Abdomen dull olive-brown; spinners paler. 
Carapace a little longer than broad; cephalic area more than 
half as long as carapace ; strongly gibbous immediately in front of 
central fovea, slightly bilobate longitudinally, gradually depressed 
to margin of clypeus. Cephalic and thoracic indentations short 
but deeply impressed, especially the posterior pair. Central fovea 
deep, procurved. Margin of carapace raised and sinuous towards 
base, the latter truncate. 
Eyes in two separate groups. Anterior laterals circular, situated 
on a bilobate tubercle at the margin of the clypeus; less than half 
a diameter apart. Anterior centrals and posteriors situated on a 
low tumulus, two full diameters of the former behind the anterior 
laterals. Anterior centrals circular, half a diameter apart, not 
quite one diameter from lateral posteriors ; the latter ellipsoidal, 
very narrow, and pointed behind. Posterior centrals two full 
diameters apart, nearly one diameter from posterior laterals, half 
a diameter from anterior centrals. Posterior row only slightly 
procurved. 
Mandibles furnished with a rastellum formed of numerous stout 
conical teeth projecting beyond the apex. Fang-groove fringed 
on both sides with rufous hairs; inner margin armed with a row 
of eleven irregular stout teeth. Floor of fang-groove studded with 
a short row of five small teeth opposite nos. 7 and 11 of the inner 
row. 
Labium as broad as long, narrowed towards apex, bears two 
stout cusps situated transversely in the centre. Cowa of pedipalp 
double its breadth ; anterior apical angle slightly produced and 
armed with a cluster of 5 or 6 stout cusps. Anterior basal angle 
armed with a curving row of 5 or 6 cusps, while the whole inner 
surface is studded with numerous small cusps. 
Sternum longer than broad, convex, smooth, set with stiff, black, 
scattered hairs. Sigillai., ii., and ii. present; the first two mar- 
ginal and indistinct, the latter submarginal, distinct, and situate 
opposite the coxa of the second pair of legs. 
Legs 4,1, 3,2. Femora without spines; tibia, protarsus, and 
tarsus of first pair armed with cusps on both sides, more numerous 
on the outer side. Tibia ii. armed with numerous cusps on inner 
margin only, with two long spines and two minute cusps only on 
outer margin. Protarsus ii. with numerous cusps on the inner 
side; on the outer several cusps and three short, stout spines, in 
a longitudinal row, beneath. Tarsus ii. armed on both sides with 
cusps. Tibie iii. and iv. without spines or cusps. Patella ii. with 
cusps on outer side; protarsus iii. with spines and cusps, on 
either side, above; and below in a series of 2—2—2. ‘Tarsus 11. 
with a few short cusp-like spines on either side. Patella and 
