THORELL ON ARANE^ OF COLORADO. 517 



sbort-uecked decanter; its anterior very narrow portion (the neck) is 

 short, dilated, and somewhat cloven at the apex, the posterior i)ortion 

 is rounded at the sides, slight! j tapering backward from the middle, 

 at least as long as broad ; the vulva is through its whole length inter- 

 sected by a narrow septum, which in front, in the anterior third part of 

 its length, has the form of a fine costa, then becomes somewhat broader, 

 gradually but very slightly increasing in breadth backward ; this 

 septum, which is narrower than the depressed parts of the vulva on 

 each side of it, and does not fill up the space between the lateral 

 margins of the vulva behind, shows a fine longitudinal costa above, 

 which is cloven at its posterior apex, here including a small triangular 

 space. In the bottom of the vulva, on each side, toward the posterior 

 apex of the septum, is seen a small shining tubercle or costa. 



The color of the female does not differ materially from that of the 

 male; the cephalothorax shows, however, besides the pale middle band, 

 also a few pale spots and streaks on each side, forming a narrow broken 

 supramarginal band. The jicilpi are yellowish-brown, with black spots 

 and rings, especially on the femoral joint; the legs are more evidently 

 annulated than in the male; the thighs have a transverse pale band 

 above, between two geminated pale patches, one "at the apex, the other 

 at the base. The vulva is dark brown, the septum yellowish, the 

 tubercles in the bottom black. 



?. — Length of body 9, of cephalothorax 4^ millim.; breadth of cepha- 

 lothorax 3J millim. Length of legs: I 13, II 12^, III nearly 13; patella 

 + tibia IV 5 millim. 



The collection contains only two examples of this S])ecies, a male cap- 

 tured on Pike's Peak, 13,000 feet above the level of the sea, July 14, and 

 a bare-rubbed female found at Kelso Cabin, Colo., July 6. L. iracunda is 

 no doubt very closely allied to L. grcenlandica Thos. (from Greenland and 

 Labrador), and it is possible that it may turn out to be a variety only of 

 that species; but as it shows some slight deviations from the description 

 of L. grcenlandica, of which I at present have no specimens to compare, 

 I have thought it safest to describe this form as a separate species. 



27. L. sinistra u. 



Very hairy, almost totally black, with some paler streaks and spots 

 on the extremities ; fourth pair of legs nearly four times as long as 

 cephalothorax; third pair of legs slightly longer than first and second 

 pairs; tarsal joint of the black-haired male palpi as long as the two pre- 

 ceding joints together, as broad as the fore thighs, half as long again as 

 broad; the genital bulb very high behind, transversely excavated in 

 front, with a very coarse, forward-directed, prominent tooth issuing from 

 the fovea of the elevated portion, and with an outward-directed spine 

 proceeding from the base of this tooth, the apex of the spine being 

 free, the bnlb also armed with a downward-directed spine at the outer 

 margin ; vulva consisting of a large oblong fovea, about double as uar- 



