88 PSYCHE, [July— August iSSS. 



h. Crest strongly elevated and surmounted by a horse-shoe 

 shaped ridge ; lobe of right clasp greatly expanded, 

 broadest apically horatuis. 



c. Crest forming a gibbous prickly protuberance ; lobe of 



right clas]^ greatly expanded, broadest basally tcrentizis. 



B. With or without subapical spots. [Terminal hooks of upper 



organ separate] ; blade of clasps moderately long as 

 compared to the main body. [Costal fold furnished 

 with long pediform bristles, curving at base, and 

 apple-seed shaped scales, but with no thread-tipped 

 tapering scales nor twisted ribbons]. 



a. With subapical spots. Right clasp with a slightly 



prominent median denticle ; beyond the bend moder- 

 ately produced martialis. 



b. Without subapical spots. Right clasp with a somewhat 



prominent median denticle ; beyond the bend much 



produced aftsom'ns. 



C. No subapical spots. Terminal hooks of upper organ consolidated 



and stout ; blades of clasps very short when compared 

 with the main body. Costal fold furnished with 

 thread-tipped tapering scales or twisted ribbons, but 

 with no long pediform bristles, or apple-seed like 

 scales, or 3-pronged rod-like scales. 



a. Of moderate size. Blade of right clasp stout. Costal 



fold with twisted riblion-like scales brizo. 



b. Of small size. Blade of right clasp slender. Costal fold 



with thread-tipped tapering scales icelus. 



THE USE OF TWO DOORS IN A TRAP-DOOR SPIDER'S NEST. 



BY GEORGE F. ATKINSON, COLUMBIA, S. C. 



Certainof the species of A77;«e.s-/rt', the tube. Mr. Moggridgc supposed the 



habits of which Mr. Moggridge studied, use of the branch and second door was 



make two trap-doors to their nests, one to artbrd the spider a means of escape 



atthesurfaceof ground at the upper end when pursued by an enemy. When 



of the main tube, the other a short dis- chased into the main tube, the spider 



tance below at the beginning of a l^-anch would g-o into the branch and close the 



