64 TERTIARY INSECTS OF NORTH AMERICA. 



2. Clubiona arcaka. 

 PI. 11, Fig. 4 ( <? ). 



Male. — Cephalothorax roundish oval, about one-third longer than broad, 

 the cephalic and thoracic portions completely blended, the front in the single 

 individual obscure with no trace of eyes. Cheliceres apparently pretty 

 large, the palpi very long, longer than the prothorax, the last joint large and 

 swollen, ovate, more than half as long again as broad, and black. Abdomen 

 a little paler than the brownish cephalothorax, long ov^ate, considerably 

 longer and somewhat broader than the cephalothorax. Legs not very long, 

 tapering considerably, amply provided with more or less divergent slender 

 spines as long as or slightly longer than the femora. 



Female. — Cephalothorax ovate, about one-third longer than broad, the 

 cephalic and thoracic portions completely blended. Palpi nearly or quite 

 as long as the cephalothorax. Abdomen sometimes lighter than the cepha- 

 lothorax, long ovate, considerably longer and sometimes a little broader than 

 it. Legs as in the male, the spines perhaps a little shorter, and on the tarsi 

 arranged to a certain extent in rows, not noticeable on the male. 



Length of body, S 5.25°"", ? 6.65'°'°; of cephalothorax, $ L75°"°, ? 

 2.15"°"; of abdomen, S 3.5'°°', $ 4.5°'°'; breadth of cephalothorax, c? 1.3'°°', 2 

 1.4"°'; of abdomen, $ 1.4°'°', $ 1.75'°°'; extent of palpi beyond cephalotho- 

 rax, S 2™°', ? 2°'°'; longer diameter of last palpal joint,,? 1.15"°', shorter 

 diameter, S 0.5°'°' ; length of first pair of legs, $ 7.5°"°, $ 6.75"°' ; its femora, 

 <? 2.05"°', $ 2.4"" ; tibiae, S 2.9"", ? 2.35"" ; tarsi, S 2.55"", ? 2"" ; second 

 pair, i 6.45™", ? 6"" ; its femora, <? 1.8"", 2 2.2"" ; tibise, S 2.5"", $ 1.65""; 

 tarsi, S 2.35"", S 2.15'°" ; third pair, S 5.35"°', ? 5.5""; its femora, S 1.35"", ? 

 1.8""; tibiaj, <? 2"", 2 1.85"" ; tarsi, $ 2"", 2 1.85""; fourth pair, S l.Td"""", 

 2 8.3"" ; its femora, <? 2.15"", 2 3"" ; tibise, S 2.6"", 22.55"" ; tarsi, c? 3"", 

 2 2.75"". 



This species agrees very well in size with C eversa (only males of 

 course compared), or is slightly smaller, and the legs if anything a little 

 longer; the cephalothorax is rounder and the palpal swelling much more 

 elongated. It is somewhat like both C. sericea and C. lanata of the Prussian 

 amber, but is somewhat smaller and has longer legs than they. 



Florissant. One <?, No. 2831; three 2 , Nos. 3253, 7087, 8082, besides 

 a 2 from the Princeton collection, Nos. 1.807 and 1.819. 



