C. E. Beeoher — Arthrolycosa antiqua. 221 



elements, and near the center of the posterior half, there is a 

 sharp transverse ridge extending about two-thirds across the 

 body. The anterior border presents a conical elevation meas- 

 uring 3 mm in transverse diameter, and showing on its summit 

 two oval prominences in which the ocelli were undoubtedly 

 located. Two of them seem to be distinctly marked and are 

 represented in the figure, while the others are obscurely shown 

 and are not delineated. 



Both mandibles are well preserved, and consist apparently of 

 a short basal joint and a strong arched angular grooved ter- 

 minal portion. Their position and character seem to indicate 

 that they were moved vertically as in the Territelarise (Avicu- 

 laria = Mygale), and not laterally as in the majority of spiders. 

 They project 3 mm beyond the margin of the carapace, and 

 extend downward a distance of at least l # 5 mm . 



The palpi are shorter and more slender than the legs, and to 

 all appearances simply terminated, except that the inner edge 

 of the extremity is marked by a small excavate area which may 

 indicate the male palpal organs. Three or four joints can be 

 made out, each being marked by a longitudinal ridge. Entire 

 length observed, 6 mm . 



The four pairs of ambulatory appendages differ little in 

 character and can be homologized, joint for joint, with the 

 Tetrapneumones. The two anterior pairs are somewhat more 

 robust than the others, but present the same general features. 

 Beginning with the distal joint as preserved on the second pair 

 of legs, it is found to measure 6 mm in length and is elongate 

 and slender in form, ending in some obscurely defined bristles 

 and claws. The surface is strongly marked by pitted pustules, 

 probably indicating the bases of the stronger hairs. The next, 

 or sixth joint, is short, not longer than wide, and without orna- 

 ment. The fifth segment is stout, measuring 7 mm in length 

 and 2 mm in width, and furnished on its distal half with a trian- 

 gular groove extending to the anterior articular face ; surface 

 with a few scattered capillary pits. The fourth and second 

 segments are short and robust, resembling the sixth, while the 

 third is similar to the fifth, but shorter and furnished with a 

 flattened margin instead of a triangular groove. As the speci- 

 men presents only the dorsal aspect, the coxal elements of the 

 limbs cannot be described. 



The abdomen is as long as the cephalothorax, but only a 

 little more than half the width of that portion. It is ovoid in 

 form, very much constricted anteriorly where it joins the 

 cephalothorax, and gradually widens posteriorly to the fifth 

 segment. The specimen preserves seven segments which grad- 

 ually decrease in length from the first to the seventh. Each is 

 ornamented with a single row of nodes on its posterior border, 



