On the inner edge of the under side of each falx is a row of teeth, and each fang is also denticulate or finely serrate, beneath towards its hinder part.
The maxillæ are strong, cylindrical, and divergent; and each has a small bluntish angular prominence at the extremity on the inner side; their inner margin has a thick fringe of pale reddish hairs, the fore surface being clothed (as ordinarily) with dark bristly hairs, and there are a few black minute tooth-like spines in a line (sometimes in a small group) near the inner corner of their base.
The labium is short, broad, its breadth nearly double its length, and the upper corners rather rounded off; there are some strongish bristles, mostly towards the apex, but no tooth-like spines nor denticulations.
The sternum is oval, rather convex, broadest towards the hinder part, which is pointed at this extremity but hollow-truncate before.
The abdomen is sparingly clothed with hairs; it is of a stoutish regular oval form, and of a dull brownish yellow colour; its fore extremity on the upper side is thickly blotched with deep blackish-brown, and the whole length spanned by a series of about five curved, or slightly angular, stoutish bars or chevrons, formed of more or less confluent, dark, blackish-brown blotches and markings; a more or less indistinct line of a similar nature also divides the fore part of the upper side of the abdomen longitudinally. There is some variety in the extent, depth, and distinctness of these markings, but the figures given ([Pl. XIX], p. 229, figs. B, B 1) show the appearance of an average example.
It must be remembered that this description is made from examples in spirit of wine, and that in life the markings (especially on the cephalothorax) are often considerably obscured by the hairs on the surface; when seen through spirit the actual tints of colour are sometimes misrepresented, but the characteristic markings are seen more distinctly.
The lower part of the sides and the underside of the abdomen are of a uniform pale dull brownish-yellow; the spinners of the superior pair are short, strong, and 2-jointed; those of the inferior pair are very minute, and near together at the base of, and almost between, the others.
Adult and immature females were found in 1873-4 abundantly at Montpellier in France, in unbranched tubular nests closed at the surface with a close-fitting "cork" lid.
In Harvesting Ants and Trap-door Spiders, p. 92, a spider inhabiting similar nests, and found commonly at Cannes and Mentone was described as N. cæmentaria, Latr. The subsequent discovery however of a very closely allied, but certainly distinct, species in abundance at Montpellier (the locality in which the original N. cæmentaria, Latr., was found) makes it more than probable that the Montpellier, and not the Mentone, species is the true N. cæmentaria. Certainly as yet no other species more likely than this to be the one described by Latreille has been found at Montpellier; in fact, the one here described is the common one found there, and alone answers to Latreille's character of having a nest with a lid of the cork type.
It has become therefore necessary now to record the Mentone species under another name, and under that name, "N. Moggridgii" (p. 273) will be noted the specific differences by which the two species may be at once distinguished from each other.