176 ENTOMOLOGICAL SOCIETY 



is an approach to it ; its motions are very illusive. In Micaria 

 the cephalothorax is elongated, but not constricted ; the abdo 

 men has a slight constriction near the front end. The legs are 

 very long and slender. But the best effect is produced by its 

 scales, most beautifully iridescent. A white band sometimes 

 interrupted is at the constriction sometimes another behind 

 this one. I have seen M. longipes running on the ground near 

 ants of similar size, though it was more often seen alone. 

 Another species of Micaria I took on the flowers of a Solidago, 

 among ants of the same size, and in my net both ran around in 

 the same manner. The Micaria seemed a little over-anxious. 

 Though Thargalia has not been modified in structure as much 

 as the other forms, its mimicry of an ant is extremely close. 

 In central New York there is a black species with one white 

 band which lives among the large black ants that are common 

 under leaves in the woods. The Thargalia is of the same 

 size, when adult, and its movements are quite similar. In 

 Texas I have seen another species of Thargalia which mimics 

 the ' 'Agricultural Ants ' ' that are common on the ground in 

 that locality. It is of the same red color, is of the same size, 

 when adult, and can move as rapidly and irregularly as the 

 ant. Several times have I seen it in "ant clearings," and it 

 was not disturbed by the sagacious inhabitants. 



I have never yet seen any of these spiders eating ants, and I 

 do not believe that they do, for an ant has a pretty hard skin 

 for a spider to bite through. Their mimicry is of the most 

 value to them as a protection. Thus, in review, one sees that 

 these forms have not had any of their important characters 

 modified for the purpose of deception, but similar results have 

 been reached by modifications of some unimportant .parts. The 

 deception is superficial, they remain good at heart. 



Mr. Schwarz remarked that Thargalia resembled ants, and 

 since on Mr. Banks' statement it was found only in company 

 with these insects, it may be considered as truly myrmeco- 

 philous, deriving more benefit from the ants than is implied in 

 the term protective-mimicry. 



In answer to a question by Mr. Howard, Mr. Banks stated 

 that the resemblance of these spiders to ants was not especially 

 protective, although it may protect them from the attacks of 

 wasps. The benefit probably comes in enabling them to more 

 easily approach and seize their prey. 



