106 ARANEIDEA. 
in front of them a rather conspicuous plate, whose posterior edge being free, probably covers the orifice of 
a spiracular organ.) 
The spider on which this genus is founded is remarkable on account of the mode of 
articulation and movement of the fangs of the falces. This has hitherto been consi- 
dered a primary differential character between the Theraphoside and all other spiders. 
We have here, therefore, a manifest transition from the Theraphoside to the Drasside, 
perhaps through the Dysderide. 
Delozeugma formidabile, sp. n. 
Adult male, length 5 lines; length of the cephalothorax very nearly 3 lines ; length of the falces slightly over 
2 lines. 
The cephalothoraa is of a deep rich black-brown colour, tinged with reddish ; its surface is thickly covered. 
with minute granulations. The normal grooves and indentations are very slightly indicated. 
The eyes of the hind-central pair are further from each other than each is from the hind-lateral eye on its side, 
and the interval between those of the fore-central pair, which are the largest of the eight, is less than a 
diameter, these two eyes being seated on a prominence of the ocular space with a vertical position. The 
height of the clypeus (which is much impressed) is not much greater than the diameter of one of the 
fore-central eyes. 
The legs are yellow-brown (only those of the third and fourth pairs remain, and on these spines are present 
on the femora, tibie, and metatarsi). 
The palpi are moderately long, yellow-brown, the digital joint dark brown. The cubital joint is slightly 
clavate ; the radial joint is longer than the cubital, somewhat produced in front at the anterior extremity, 
and on the outer side is a moderately long apophysis of a somewhat flattened or flap-like form, truncated 
at its extremity ; beneath the humeral joint on its posterior half are five or six erect bristles in a longi- 
tudinal line, and three fine short spines on the fore part of the upperside. 
Falces long, prominent, subcylindrical, straight, with two long strong sharp teeth beneath rather towards the 
outer side ; the longest of these teeth is in the middle and directed obliquely forwards, the other is towards 
the base near the extremity of the maxilla, and vertical. The fangs are as long as the falces, and very 
slightly curved; beneath each a little way forwards from its insertion is a strong nearly vertical tooth. 
The fangs when at rest lie along the underside of the falces close up to the two long teeth above noted. 
The falces are similar to the cephalothorax in colour, and also in being covered along the upperside with 
minute granulations ; the sides being glossy and smooth. 
The maxilla, labium, and sternum are dark yellow-brown. 
The abdomen, which is much shrunken, appears to be oblong-oval in form, of a yellow-brown colour, palest 
along the upperside, and furnished with short hairs. 
Hab. Mexico, Guanajuato (Alfred Dugeés). 
The description is taken from a dry and much injured specimen kindly communicated 
to me by Prof. Alphonse Herrera, of the National Mexican Museum. 
MACROPHYES, gen. nov. (Drasside). 
Cephalothoraw short, oval, but longer than broad, somewhat flattened above, truncate before ; profile line level 
to the eyes, with the slightest possible impression at the junction of the caput and thorax. 
yes small, tolerably closely grouped, and not greatly different in relative size, except the fore-centrals, which 
are much the smallest, in two transverse rows, very slightly curved away from each other ; the anterior 
row shortest. Ocular area slightly prominent, and sloping a very little forwards, the clypeus low. 
Legs 1, 4, 2, 3, very long, slender, furnished thinly with fine hairs, and armed with long slender spines, those 
beneath the tibize of the first and second pairs arranged in a series of pairs. The tarsi end with two 
curved pectinated claws, beneath which is a small scopula. 
