OF WASHINGTON, VOLUME XII, HHU. 97 



is a little broader than the basal segment of the antenna, but 

 does not project beyond it. 



"Length: Prouotum, 10 mm.; femora, 23 mm. ; ovipositor, 

 10 mm. 



"Type: No. 12918, U. S. National Museum. 



"This species was collected in bromelias." 



-A note by Mr. W. D. Pierce on the nest-building habits of 

 Pogonomyrmex barbatus molefaciens Buckley was presented: 



"Having in mind a discussion of the construction of nests 

 by Pogonomyrmex ants in the West which was taken up by 

 the Society at its meeting February 10, 1906, I wish to add 

 the following interesting notes. 



"On July, 23, 1907, at Childress, Texas, I was very much 

 surprised to find a nest of Pogonomyrmex barbatus molefaciens 

 Buckley with two openings about 10 inches apart, each 

 of whicn was the center of a wreath-like mound of the hull 

 of a common grass. This grass has been determined for me 

 by the botanists of the Department of Agriculture as Andro- 

 pogou torreyanus Steud. (Amphilopis torreyanus Nash. ) Two 

 wreaths were interlocked about 1 foot in diameter each, 

 and 2 to 3 inches thick, composed of nothing but the hulls 

 of this one species of grass. No other nests in the vicin- 

 ity had this strange character. I have never since then seen 

 any nests of this species quite so strange. 



"At the same time and not so very far distant from this pe- 

 culiar nest was the nest of another colony of the same ant 

 which was shared with an equally large colony of Stenamma 

 {Ischnomyrmx) cockerelli Andre. The two species seem to 

 live together in perfect harmony. The immediate surround- 

 ings of the nest were composed entirely of little pellets of red 

 earth, while in an outer circle with a radius of over a foot was 

 a ring of black cinders about a quarter of an inch in diameter. 

 As I have never noticed a colony of Pogonomyrex associated 

 with any other ant, I assume that this note may be of impor- 

 tance. 



"While I have no definite observations on record concerning 

 the activity of Pogonomyrmex, I have nevertheless observed 

 that this ant is most active in the hottest part of the day. 

 The most noticeable exception to this activity which I have 

 noticed was during the month of August, 1909, when the tem- 

 perature was above 100 F. most of the time. It was very 

 noticeable that the Pogonomyrmex did not come out of their 

 nests during the hottest part of the day, especially when the 



