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ART. XV,-DESCRIPTIONS OF THE ARANEÆ COLLECTED IN

COLORADO IN 1875 BY A. S. PACKARD, JR., M. D.

BY T. THORELL, PH.D.,
Junior Professor of Zoology in the Unirersity of Upsala, Sweden.

CLASS ARACHNOIDEA.

Order ARANEÆ.

Section* ORBITELARIÆ.

Fam. EPEIROIDE.

Subfam. EPEIRIN.

Gen. EPEIRA (Walck.), 1805.

1. E. trivittata Keyserl. SYN.—1864.Epeira trivitatta Keyserl., Beschr. nener ... Orbitelæ, in Sitzungs

ber. d. Isis zu Dresden, 1863, p. 95 (33), tab. v, figg. 6–9.

One adult male and several young examples of both sexes were captured by Dr. Packard at Boulder, Colo., June 29.

This species is probably nearly related to E. domiciliorum Hentz, but it is much smaller, the full-grown female being only about 7–8 millim. in length, and the male about 6 millim. It appears to be common in the United States, and has perhaps been described both by Walckenaer and Hentz, though I am unable to identify it with any of the species of these authors.

Gen. TETRAGNATHA Latr., 1804.

2. T. elongata Walck. SYN.--1841.— Tetragnatha elongata Walck., H. N. d. Ins. Apt., ii, p. 211. 1850.Tetragnatha grallator Hentz, Descr. and Fig. of the Aran. of the

United States, in Bost. Journ. Nat. Hist., vi, p. 26, pl. iv, figs. 1, 2. 1865.—Tetragnatha grallator Keyserl., Beitr. z. Kenntn. d. Orbitelæ, in

Verhandl. d. zool.-bot. Gesellsch. in Wien, xv, p. 850 (52), tab.

xxi (iv), figs. 24-27. As this spider is very variable, and the above synonyms not quite sure, I shall here give the characteristics of the species and of its principal varieties known to me.

* Reasonable objections having been made (by Gerstaecker) against calling the principal groups of the order Aranea “suborders”, I have here adopted the more indifferent term “ sections ".

477

T. elongata Walck.-Space between the two lateral eyes smaller than that between the posterior central and lateral eyes, smaller, or at least not larger, than the space between the anterior and posterior central eyes. Length of mandibles of male about nine-tenths of the length of cephalothorax, armed above, toward the extremity, with only a strong tapering spine, emarginated at the truncated apex; the anterior margin of the claw-furrow is provided with at least 8 teeth; first tooth small; second larger, directed somewhat backward; third very long and strong; the distance between first and second larger than (in general, about double as large as) that between second and third, and rather larger tlian the space between third and fourth, which is at least double as large as that between fourth and fifth; the posterior margin has also about 8 teeth; first small; second rather long and strong; the following smaller; the distance between first and second smaller than that between second and third, which is about double that between third and fourth. Mandibles of female about two-thirds as long as the cephalothorax; the claw-furrow is armed on the anterior margin with about 8 teeth; first somewhat stronger than the following, (generally) removed irom second by a very long toothless space, and placed opposite to the fourth teeth of the posterior margin, the first tooth of which is in general much farther removed from the second than this from the next following; the claw of mandible is provided with a small protuberance near the base on the outer side. The tibial part of the male palpus longer than the patella, its long apophysis being provided with a protuberance toward the middle of the inner side. Legs testaceous, their joints more or less evidently brownish or blackish at the apices, the metatarsus and tarsus of the first pair of legs together shorter than patella, tibia, metatarsus, and tarsus of the fourth pair of legs; belly blackish, with two more or less distinct parallel yellow longitudinal bands.-- fad. Length 4-10 millian.

Forma principalis.-Interval between the two lateral eyes much smaller than that between the anterior and posterior centrals; tibial joint of the male palpi at least half as long again as the patellar joint; cephalothorax brownish-yellow, sometimes sooty at the margins, and then provided with a sooty V anteriorly ; sternum brownish-yellow, sometimes blackish at the margins; abdomen brownish or yellowish, with a ramified longitudinal black line along the back and often an undulated paler band on each side.

9.-Length of body 81 millim.; length of cephalothorax 3, breadth of same 2 millim.; length of mandibles 2, of palpi 4 millim. Legs: I 21, II 151, III 8}, IV 123 millim.; metat. + tars. I 8, pat. + tib. + metat. + tars. IV 82 millim.

8.-Length of body 63, of cephaloth. nearly 2 millim.; breadth of cephaloth. 13 millim.; length of mandibles 21, of palpi 4 millim. Legs: I 214, II 16, III 72, IV 133 millim.; metat. + tars. I 8, pat. + tib. + metat. + tars. IV 82 millim.

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