156 MR. F. PICKARD-CAMBRIDGE ON NEW SPIDERS. [ Feb. 17, 
abdomen. Lateral area mottled with dusky brown; ventral 
surface pale yellow, unicolorous. Legs entirely yellow: 1. and i. 
very faintly annulated and speckled with dusky brown, ili. and iv. 
annulated, in some cases very richly, with black or brown. 
Mandibles ved-yellow, with a large brown patch on each in front. 
N.B.—These colours are very variable and in some cases the 
central dark band within the inner pale band on the abdomen 
is itself pale. 
The vulva consists of two parallel plates, which have a promi- 
nent angle on their inner margin. Between these, in front, lies 
a deep transverse semicircular depression, and a convex central 
piece, with a few shallow longitudinal grooves, is situated between 
the plates. 
For figures of tibial spur of male palpyus and the vulva, see 
Plate XIV. figs. 7, 9. 
These spiders are very abundant on the Lower Amazons, racing 
over the surface of the water with legs extended and body flat, 
and are exceedingly difficult to catch. None of the females had 
egg-cocoons with them, but they probably carry them in the same 
position as Z'rechalea, for in habits and general appearance these 
spiders are very similar to those belonging to the latter genus. 
Hab. Lowrr Amazons: Breves, Parana Buyassu (/. P.-C., 
1895-6). 
Genus THanatipius EK. Simon. 
Hist. Nat. Ar. 2, ii. p. 293. Type, 7. dubiws (Hentz). 
N. America. 
The following three species are referred to this genus by 
Simon :— 
1. 7. dubius (Hentz), Bost. J. N. H. v. p. 449 (1847). 
(Sub Zhomisus.) 
he TUE ueeqooIs (Valentws)), Oe, Gittis oho ocassosacc09 080007 (Sub Zhomisus.) 
3. 7’. undulatus (Keys.), Verh. z.-b. Ges. Wien, p. 486 (1887). 
(Sub Zetragonophthalma.) 
4, THANATIDIUS SPINIPES, sp. nov. (Plate XIV. figs. 10-12.) 
Type @ in coll. Brit. Mus. Total length 6 mm. 
Hab. Parana Buyassu, Breves, Lower Amazons. 
? .—Colour. Carapace, mandibles, sternum, and legs bright, 
unicolorous orange. Abdomen olive-green, with a central band 
of cretaceous-white pigment-cells. 
Structure. Carapace nearly circular, ocular region produced, 
parallel-sided, slightly raised. Thoracic region gibbous, abruptly 
deflected behind. Hyes: posterior row strongly recurved, eyes 
subequal, less than one diameter apart, equidistant ; laterals on a 
stout conical tubercle. Anterior row strongly procurved; eye- 
tubercles subequal, less than one diameter apart, equidistant, much 
wider than the width occupied by lateral posteriors. Clypeus, 
in centre as high as four diameters of anterior central eyes. 
