224 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



mandibles are cylindrical, arched at the base, glossy, and slightly pubescent; yellow, with 

 darker shades at the base. 



ABDOMEN : Well arched, rounded to the spinnerets, which are situated well under the 

 apex. The dorsum is marked by a broad black median band, varying but little in width 

 from base to apex, but with contractions at two points near the middle; whitish yellow 

 marginal bands mark the outlines, and double rows of whitish spots symmetrically arranged 

 are grouped along the median band on each side the median line. The sides are marked 

 by whitish yellow irregular patches, running longitudinally along the base, but on the sides 

 and towards the apex sloping to the spinnerets. Beneath the abdomen is dark brown, the 

 venter marked by two whitish yellow broken lines, well separated, running from the 

 epigynum to the spinnerets ; within these, symmetrically arranged on either side of the 

 median line, are buttonlike rows of whitish yellow spots, unequal in size, and somewhat 

 narrowing toward the spinnerets. The epigynum is without a prolonged scapus, and shows 

 simply a cuplike atriolum, separated into two chambers, within which the opening of the 

 oviducts appear. (Plate I., Fig. 5.) 



This beautiful specimen, by the flat form of its cephalothorax and the location of the 

 spinnerets beneath the abdomen, approaches Argiope more closely than the typical Epeira. 

 The eyes, however, more closely resemble those of Epeira, the front row being recurved, as 

 in Epeira, instead of procurved, as usual in Argiope. The rear row also is but slightly 

 procurved, as in Epeira, instead of greatly procurved, as in the typical Argiope. For this 

 reason I place it here rather than create for it a new genus, which might perhaps properly 

 be done, as a connecting link between Argiope and Epeira. 



DISTRIBUTION: Fort Yuma, Arizona. (Marx Collection.) Only a single specimen col- 

 lected. 



GENUS CYCLOSA, MENGE, 1876. 



In Cyclosa the cephalothorax is cordate or oval, the head arched and elevated 

 above the corselet. The sternum is wide at the base, somewhat longer than broad. The 

 maxillae are as in Epeira. The labium is relatively smaller. The eyes are divided into 

 three groups ; the front eyes of the central group upon a projecting eminence ; the quad 

 longer than wide ; the clypeus is moderately high ; the sidefront eyes are divided from the 

 midfront by a space greater than that which separates themselves; the front row is decidedly 

 recurved, the rear row aligned, or nearly so. The legs are, in order of length, 1, 2, 4, 3; 

 stout, rather scantily pubescent, the spines being long, thin, and aculeate. The abdomen 

 is an irregular oval, thickest at the apex, marked in some species by shoulder humps, and 

 in others by a conical projection from the dorsal median that has the appearance of a tail. 

 The apical wall is high, the venter conical, and the spinnerets situated well beneath the 

 middle part thereof. 



No. 76. Cyclosa turbinata (WALCKEXAER). Plate XVII, Figs. 5, 6. 



1842. Epeira turbinata, WALCKENAER . Ins. Apt., ii., p. 140. 



1860. Epeira caudata, HENTZ J. B. S., vi., p. 23 ; Sp. U. S., p. 126. 



1888. Cyclosa turbinata, McCooK . . . Revised Nomenclature, Proceed. Acad. N. S., Phila. 



1889. Cyclosa caudata, McCooK .... Amer. Spiders and their Spinningwork, I., II. 



1890. Oyclosa turbinata, MARX .... Catalogue, p. 549. 



FEMALE: Total length, 5 mm.; cephalothorax, 1.7 mm. long, middle width 1.2 mm., 

 front width 0.7 mm. ; abdomen, 3.4 mm. long, 2 mm. wide. 



CEPHALQTHORAX : Corselet a rounded oval ; caput and the somewhat higher anterior 

 part of the corselet are roundly arched; cephalic suture deep; the fosse small; sternum flat, 

 longer than broad; maxillze and labium broader than long; color, as also sternum and 

 mouth parts, dark brown or black. 



EYES: Ocular quad somewhat longer than broad, wider in front than behind; MF 

 separated by about 1.3 diameter; MR smaller than MF, and separated by less than their 



