ARACIIX1DES AKANi:iDES LATEUK'.KAD.i: 57 



TIIOMISCS Walckenaer. 



Three species of Thomisides occur in the Tertiaries of Colorado, and 

 apparentiv all of them - mutilated) belong to the true Tliomisina-, in 



which the hinder two pairs of legs are much weaker than the others. As 

 tire cephalothorax is in all cases poorly preserved or lost, it is impossible to 

 speak at all definitely of their generic relations, and therefore I have placed 

 all of them in (lie tvpical genus Thoinisus, from which the family derives 

 its name, and which, or Xysticns, its near ally, they closely resemble in 

 general appearance. In all the abdomen is nearly round. It is interesting 

 to find, as observed above, that the species of this family from the stratified 

 deposits of the Kuropean Tertiaries have also been placed in Thomisus and 

 Xysticns, though none of them appear to lie very closely allied to our 



ie.s. 



This genus is widelv spread, lint nearly all the species belong to the 

 warm temperate regions of Knrope and North America. (November, 1881.) 



of Tlioinisut. 



Ti'iu of liinilcr : %a lii-'iii'l'-r :il IIP th.n :ml inndi linailcr tli:in Ilir l:irsi. . .1. T. r< 



Tililli' of lllH'li T |i:lir-. "I lr'4-t ol ( i|u:il tilth thrOllghotlt. 



- : iVuiiiri <>!' lir-l ii:iir Hi' ! IIMIL; :\. mi :is tboaoof Second pair ; l:irsi :ishio;ul 



............................................................... ~. '/'. ili'jiini-liiH. 



Lar^o spci-i.-s; t'i'iiiur.i nl lir,i :in.| Wi ...... I pain of lees Ol al"iut r^ual Irn^lli; hi^t t :i rs;il joint 



Hlriidrrcr ilia ii tin- tilii;r .................................................... > T. dtj'ossua. 



1. TlloMlsi's RE8UTU8. 

 I'l. n, KI-. i:;. 



Abdomen plump, short ovate, about a fourth longer a^'ain than broad, 

 the base broad, the sides well rounded, the hinder extremity full, with the 

 extreme apex squarely truncate. Onlv a fragment of' the cephalothorax 

 remains, showing th" lir.iad attachment of the abdomen. The two hinder 

 pairs of le^-s only are preserved, showing limbs of considerable length, bent 

 forward, the femora nearly as loii^- as the abdomen, longer than the tibia. 1 

 and flattened, largest in the middle; the tibi;e are straight, completely con- 

 solidated with the first tarsal joint as in spiders generally, also flattened, 

 slender at base and graduallv though slightly increasing in si/.e apically, a 

 peculiarity which is not shown in the plate; the tarsi are much slenderer, 

 not flattened, and longer than the tibia?, the first joint alone being nearly as 



