196 On new Genera and Species of Trapdoor Spiders. 
edge of mandible furnished with an external edge of 6 stout 
blunt teeth and an inner one of 4 or 5, of which the apical is 
the stronger, and on the inner side of the latter row with two 
irregular rows of smaller teeth. 
Labium long, conical, thickly clothed in its distal half with 
stout hairs, amongst which at the apex there is a thick cluster 
of spinules, which appear to have arisen from the fracture of 
stout sete. Maxille all along their inner border clothed with 
sete intermixed with spinules. 
Sternum with a deep smooth median depression on its ante- 
rior half; from the posterior end of this three pairs of shallower 
impressions, representing the normal muscular scars, radiate in 
the direction of the coxee of the first, second, and third legs. 
Falpi as long as the legs of the first pair, but stouter ; 
patella armed with a few spines amongst the sete on its inner 
surface; the tibia and tarsus with an external and internal 
cluster of stout short spines, which are much more numerous 
on the tarsus. In the first and second legs the tarsi and pro- 
tarsi are armed like the tarsus of the palp; the tibia of the 
first has from 8 to 12 spines in front and about the same 
number behind, of which the two lowest are the longest ; 
tibia of second leg with from 1 to 3 spines in front and a 
cluster of spinules behind, of which one of the lower is very 
long. Patella and tibia of third marginally spined above, 
the protarsus and tarsus also thickly spined, especially poste- 
riorly ; patella of the fourth spinulose in front ; tibia unarmed, 
protarsus with a few long spines anteriorly in its distal half ; 
tarsus also thickly spined in front. Claws of palp unarmed ; 
of leg with a single basal tooth, which is smaller on the 
posterior legs. 
Measurements in millimetres of type specimen.—Total 
length of trunk 23, of carapace 10, width 9°5; length of 
appendages from base of femur: of palp 17, of first leg 17°2, 
second leg 17:5, third leg 18, fourth leg 22°5. 
Loc. Trinidad (J. H. Hart). 
In the Ann. & Mag. Nat. Hist. (6) xi. p. 409, I identified 
the specimens here described as A. scalops, Simon (Ann. Soc. 
Ent. Fr. 1889, p. 177); but the figure that I gave of the 
nest (pl. xix. fig. 3), with its peculiarly thickened hinge, does 
not tally with that of the nest of A. scalops published by 
Simon. The specific characters, too, of scalops do not. seem 
applicable to S. Hartii. For instance, we are led to infer 
that the tibia of the second leg is unarmed in front and that 
the tibia of the first has fewer spines in scalops than in Hartt. 
It is interesting to record that in young specimens 11 millim. 
in length the spme-armature of the appendages is weaker and 
