240 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



and delicate formation and colors, the shape of the cephalothorax and abdomen, and, in 

 part, the structure and armature of the legs, they at once strike the eye as quite different. 

 A special difference is noted in the structure of the cephalothorax, which in Epeira is 

 rather low, of almost equal thickness throughout, rising gradually from the margin of the 

 corselet to the fosse. In Abbotia, on the contrary, the corselet, as viewed from the side, is 

 a truncated cone in shape (Plate XX., Fig. 17), rising rather abruptly from the margin to 

 the crest, which is comparatively high, and cleft into two parts by the longitudinal fosse. 

 The head, again, is more depressed than in the typical Epeira, sloping forward from the 

 fosse, with an incline somewhat less than that of the base, which slopes downward rather 

 abruptly. The legs are relatively not so short and stout as in Epeira (except at the 

 femora, which are strong), are less heavily clothed with pubescence; the spines compara- 

 tively few, and longer and thinner than in typical Epeira. The face is somewhat narrower 

 than that of the typical Epeira, but not widely different. The eyes resemble those of 

 Epeira, but the intervening space between the sidefront and the midfront eyes is relatively 

 not quite so great, in. the typical Epeira being from 2 to 2.5 times that of the intervening 

 space of the midfront eyes, while in Abbotia the space is not greater than 1.5 that interval. 

 The abdomen (Figs. 7, 7a), instead of having the subtriangular, subglobose, or oval form 

 of Epeira, is a decided ovate, contracted at the base and widening toward the apex, where 

 it is again somewhat narrowed. The known species make horizontal, orbicular webs, but 

 occupy an adjacent shelter of retitelarian lines, underneath which they hang, back down- 

 ward, clasping a trapline that unites the shelter to the orb. 



No. 92. Abbotia gibberosa (HENTZ). Plate XX, Figs. 7, 8; PI. XXIV, Figs. 4, 4a, 4b. 



1847. Epeira gibberosa, HENTZ . . . . J. B. S., v., p. 457 ; Sp. U. S., 119, xiii., 20. 



1884. Epeira gibberosa, EMERTON . . . N. E. Ep., p. 317, xxxiv., 17. 



1889. Epeira gibberosa, McCoOK .... Amer. Spiders and their Spinningwork, Vol. I. 



1889. Epeira gibberosa, MARX Catalogue, p. 545. 



FEMALE: Total length, 4 mm.; cephalothorax, 1.75 mm. long, 1 mm. wide; abdomen, 

 3.3 mm. long, 2 mm. wide. 



CEPHALOTHORAX : High, peaked ; the centre cleft with a longitudinal fosse ; sloping 

 sharply downward to the roundly truncated base, which is slightly indented, sloping also 

 forward at a less angle to the face ; the cephalothorax, from the side, presents the view of 

 a truncated cone ; corselet grooves distinct ; cephalic suture well marked ; color green or 

 greenish yellow (which in alcohol becomes yellow), with a brownish crest; caput depressed 

 below the summit of corselet, and slopes well to the eye space; color rather lighter than 

 the corselet, covered with yellowish pubescence, thicker at the face, where the head is 

 narrowed. The sternum is broadly shield shaped, rather squarely truncate at the base, not 

 sharply pointed at the apex, almost as wide as long; with sternal cones, especially in front 

 of coxa-I ; rather elevated and rounded at the centre ; sparsely covered with brownish 

 bristles ; color in alcohol yellow ; the labium is rather small, subtriangular, scarcely half as 

 long as the maxillee, which are obtusely triangular at the tips, somewhat longer than wide, 

 colored as the sternum and labium. 



EYES: Ocular quad on a low eminence, projecting in front, thus giving the face a 

 somewhat compressed appearance; the quad is longer than wide, the front scarcely, or but 

 little, wider than the rear ; the eyes on black bases, and not greatly differing in size ; MF 

 and MR both separated by about one diameter; side eyes without decided tubercles, but on 

 black bases ; barely contingent ; about equal in size, smaller than the middle eyes ; the 

 space between SF and MF about one and a half to two times the intervening space of MF; 

 the space between SR and MR is somewhat greater than the above ; clypeus height about 

 one diameter MF; front eye row decidedly recurved, rear row procurved. 



LEGS: 1, 2, 4, 3; stout at the femora, and narrowing toward the feet; provided with a 

 few short and a number of long, acute, brownish spines, set in double rows upon femora 

 and tibia, and with short pubescence; a dark longitudinal band of color extends beneath 



