igil] NORDAMERIKANISCHE HyDRACHNIDEN 287 



The body-length of the single example before one is 1600^1. 



The breadth of the eye-plate in front is about 300/*, the length of 

 the capsule 200/t, length of the bridge 45/^, breadth 40 . The front 

 margin of the capsule has internally a slight rounded prominence; on 

 each side of these two prominences is a distinct hair-plate with a fine 

 short bristle. The eye-capsule is produced posteriorly into a blunt 

 point (Fig. 8). Its opening on the under side is comparatively small, 

 triangular in outline and without well developed marginal thickenings 

 (Fig. 9). The anterior eye-lens has, on the whole, an oval form, and is 

 somewhat shifted away from the capsule-margin; the posterior lens is 

 elongate-elliptical . 



The length of the capitulum on its lower wall, without the processes, 

 is about 350/*; the breadth (in the region of the oral aperture) 230/*. 

 The oral area is almost circular in its outer ring; its two axes measure 182 

 and i66/A. The oral fringe (Mundkrause) forms a somewhat smaller 

 ring. The oral aperture is not surrounded by a leaf-like pattern (Fig. 

 10), such as, j.g., occurs in E. desecta (Fig. 5). The area about the oral 

 margin is coarsely porous, the posterior part of the maxillary shield, 

 on the other hand, finely porous. Otherwise no reliable particulars con- 

 cerning the capitulum can be given, as it was much injured by its removal. 



The tracheal plates are 332/Lt long and strongly curved upwards at 

 their posterior ends. 



The mandible is 265/i long and 166/i broad. The flexor sidi is not 

 shortened, as compared with the extensor side; the former bears a rounded 

 prominence at the posterior angle; the latter, behind the sheath of the 

 mandibular class, is without an excavation. 



The maxillary palpus is, on the whole, of slender form, the terminal 

 segment much more than half as long at the penultimate segment; the 

 distal end of the latter is stouter than the proximal end. This joint 

 bears an inner series of fine, widely separated, smooth bi'istles, and at the 

 distal end some pectinate bristles arranged in tufts (Fig. 11); four smooth 

 bristles are present in the outer row. The third segment of the palpus 

 is without an opening on any side. Its process is provided with numerous, 

 moderately long, non-pectinate bristles. 



In E. triangulifera Koen., the most nearly related species, the ey^- 

 capsules differ in that they are not angularly produced behind, but are 

 rounded off, the lateral prominences at the front margin of the bridge 

 more distinct and the opening on the under side of the eye-capsule sur- 

 rounded by stouter marginal thickenings. The capitulum of E. tri- 

 angulifera, which is rounded off and considerably narrowed in front, is 

 broadest, not in the direction of the oral aperture, but farther back, 

 about the base of the large process, which forms laterally an angular 

 projection in this situation. 



