1896.] SPIDEKS IBOM THE LOWEB AMAZOWa. 725 



with a double series of from 6-7 small cusps, on either side, 

 beneath ; tarsus ii. tvithout any spines, but furnished with nume- 

 rous spiniform hairs ; tarsi iii. and iv. without spines, but armed 

 with spiniform hairs. Protarsus i. furnished with numerous stout 

 cusps beneath ; protarsus ii. with a few apical and a few other 

 spines on the undei'side ; protarsi iii. and iv. furnished with 

 numerous spines. Tibiae i. and ii. armed beneath with numerous 

 bacilliform spines. Tibiae iii. aud iv. armed with numerous spines 

 beneath. Tarsi i. and ii. three-clawed, superiors with single sub- 

 median denticle ; tarsi iii. and iv. two-clawed, superiors with single 

 submedian denticle, inferior claws obliterated. 



Spinners four : posterior pair less than one-third the length of 

 abdomen ; basal joints equal ; apical joint double the length of 

 basal : auterior pair very short, equal to basal joint, half a diameter 

 apart. 



Fang-groove furnished on both sides with a row of stiff rufous 

 hairs, those on the outer margin coarser. Moor of groove studded 

 with a double series of conical teeth, on the inner margin 14, on 

 the outer margin 10, tlie latter being the longest. Tooth no. 9 

 on outer margin is inserted opposite tooth no. 14 on the inner 

 margin. 



Comparative measurements in millimetres. — J . Carap. 5'5 long., 

 5-5 lat. Abd. 7 long., 5 lat. Ceph. area 4 long. Stern. 2-75 

 long., 3 lat. Coxa of pedipalp 2-5 long., 1 lat. Pedes, long. i. 18 

 — ii. 14-5— iii. 14— iv. 20. Artl. i. 2-6— 1—4-5— 2— 3-5— 3— 2. 

 Artl. iv. 2-25— 1—5— 2— 3-5— 4— 2. Postr. inam. 2 long. ; artl. 

 •5 — '5 — 1. Antr. mam. '5 long., '25 separ. Mandib. 2'5 long. 



In both sexes there are present on each of the last three joints 

 qf all four pairs of legs, on median line of tarsi, at base of protarsi, 

 and at base of tibiae on both sides, several small round tubercles, 

 from whose summit there issues a single, long, fine " sensory hair." 



The male and female described above were taken together beneath 

 a damp decayed log of wood in the low-lying part of the forest 

 south of Santarem, on the Lower Amazons. The feinale was 

 partially buried in the soil beneath the log, the whole body being 

 apparently bedewed with fine drops of moisture. She remained 

 perfectly motionless, and appeared as though dead and in process 

 of decomposition through what appeared to be a minute fungus. 

 The supposed fungus, however, proved to be only the papilliform 

 hairs, each with several drops of moisture on ils surface. There 

 appeared to be no tube or nest of any kind, and one is led to 

 suppose that the hairs are used for perceiving the passage of au 

 insect over the spider as it lies buried in the mud. Whether this 

 is so or not one cannot, of course, pronounce with certainty ; but 

 the encrustation of the spider with grains of grit, rendering it 

 almost invisible when half buried in the earth, would seem to point 

 to some such habit. The male, which was lying with its legs 

 gathered together, close to the female, is, however, not so encrusted 

 with grit, though the plumose papilliform hairs are very noticeable. 



