152 ARANEIDEA. 
Hab. Mexico, Venta de Zopilote in Guerrero 2800 feet (H. H. Smith). 
This pretty spider combines some remarkable characters, making it somewhat 
difficult to assign it its exact systematic position. I do not, however, think that 
further research will very materially alter that in which I have here placed it, ¢. ¢. in 
the group connecting the Theraphoside and Filistatidee with the Dysderide. Perhaps 
it comes nearest to the genus Periegops, Sim. 
SPHECOTYPUS, gen. nov. (Myrmecide). 
Cephalothorax narrow, elongate, divided into five well-marked segments by deep transverse triangulations or 
constrictions, with a pair of legs articulated to each of the four posterior segments, the caput forming 
the first segment; this part is rounded behind, but transversely truncate before, and angulated at its 
lower fore-corners, which is its widest part; the posterior extremity turns up rather abruptly above, as 
though to permit of the elevation of the abdomen; the height of the clypeus is less than half that of 
the facial space and slopes forwards. 
Eyes small, not very greatly differing in size, excepting the two central eyes of the anterior row, which are 
much the largest of the eight, the fore-laterals being the smallest; in two transverse nearly equally 
curved parallel rows, the anterior row much the shortest and slightly the most curved. 
Legs moderately long, slender, 4, 1, 2, 3, armed with a few long, fine spines on the tibie, tarsi, and metatarsi,. 
and one or two on the femora of the third and fourth pairs; they are articulated to the face of the 
sternal surface ; tarsal claws two, beneath which is a compact claw-tuft. The coxe are of inordinate size 
and length, rather bent, and those of each of the two hinder pairs are articulated very near to each other 
respectively. The sternum is therefore of an abnormal form, and at the fore extremity it is strongly bent 
inwards transversely just before the insertion of the first pair of legs. 
Falces rather short, massive, conical, the anterior sides slightly flattened, or, in fact, somewhat hollow, with 
angular margins. 
Mawille long, strong, nearly straight, narrowest across the middle just above the insertion of the palpi, and 
much broader at the top, where they are slightly rounded. 
Labium long, more than half the length of the maxillw, broader at the base than at the apex, which is trun- 
cated, broadest in the middle, just below which it is rather constricted on the margins and across the 
middle. 
Abdomen joined to the cephalothorax by a long longitudinal sheath-like pedicle, which fits into the abdomen 
in a short socket. The form of the abdomen is elongate, cylindric, oval, with a strong transverse con- 
striction towards the fore extremity ; the portion included in front of the constriction is covered with a 
coriaceous plate, at the middle of a corresponding one to which, underneath, the genital aperture is 
placed ;.behind the constriction are several transverse, dark, narrow ridges across the upperside, indi- 
cating (or simulating) a pristine segmental structure of the abdomen, the transverse ridges being apparently 
caused by folds in the epidermis. 
This genus is nearly allied to Myrmecium, Latr., but the caput is narrowest in front 
in Myrmecium, and the anterior row of eyes is straight ; the form also of the sternum 
is quite different, and also the method of articulation of the legs to the sternum: the 
cephalothorax is divided into three segments only in Myrmecium, the anterior of 
which includes not only the caput (as in the present spider), but also a portion of the 
thorax; the sternal plate beneath this portion is somewhat heart- or shield-shaped, 
much broader than any part of Sphecotypus, and to it on each side close together 
are articulated the coxe of the first and second pairs of legs, whereas in the present 
