166 PROCEEDINGS OF THE ACADEMY OF [May, 



in outline, with the posterior border truncate and concave at the 

 middle; a distinct fine median sulcus which is rather long always 

 present, as are also more or less distinctly impressed radiating striae. 

 Pars cephalica elevated and arched, distinctly separated from the par's 

 thoracica by cervical furrows which unite at an angle at the median 

 dorsal line, these more rarely indistinct above; pars cephalica with 

 front truncated or more or less obtusely rounded. The face high, 

 trapeziform or, less commonly, with the sides subparallel; in profile 

 vertical, or at least very steep. 



Eyes all of the diurnal type; always distinctly arranged in three 

 rows, of which the first is composed of four eyes and is located upon the 

 lower part of the face, the second composed of two eyes at the upper 

 part of the face or semidorsal in position, and the third, also com- 

 posed of two eyes, in a strictly dorsal position; eyes of the first row 

 small and comparatively close together, in a straight, procurved or 

 rarely recurved row, the lateral eyes on more or less evident tubercles 

 and with their visual axes directed antero-ventrally ; eyes of second 

 row very large, occupying a transverse space, in most cases wider than 

 that of the first row, less commonly of the same length or shorter, their 

 visual axes directed antero-laterally ; eyes of third row large, almost 

 always more widely separated than those of the second row, with which 

 they thus outline a trapeziform area (quadrangle of posterior eyes), 

 their visual axes directed more or less caudo-laterally. Clypeus com- 

 paratively narrow, always narrower than the width of the area out- 

 lined by the first and second rows of eyes (quadrangle of anterior eyes). 



Chelicerce long and robust, always vertical in position in both sexes ; 

 at base a well-marked and rather large lateral condyle; both upper and 

 lower margins of furrow armed, the upper with two or, more commonly, 

 with three teeth, of which the median is much the largest, and the 

 lower margin with from two to four stout conical teeth; posterior 

 face always marked with a distinct oblique stria, along the inner side of 

 which, especially in the middle region, is a well-developed, often 

 dense, pilose band ; upper margin of furrow bordered with a subdense 

 pilose band or fringe. 



Labium free; the ventral surface flat or, much more commonly, 

 convex; more or less attenuated anteriorly, with front margin truncate 

 or obtuse; from longer than wide to wider than long; much shorter 

 than the endites. Endites longer than wide, more or less excavated 

 within and fitting over the sides of the labium, externally roimded and 

 never much narrowed at base; erect, never obliquely inclined; dorsal 

 surface flat or a little concave; distally the supra-external border with 



