THE NESTING HABITS OF ANTHIDIUM. 2Q 



of the species invariably seek out the empty shells of different 

 Helices wherein to start their future family. 



Thus far, the habits of but three of the forty-one North 

 American species of Anthidium have been made known. Of 

 these emarginatum and parosclcc are " Cottonniers," and con- 

 struct their nests normally in dry sand-banks. The third 

 species, consimi'c, builds among the branches of shrubs or in 

 crevices in rocks and has habits somewhat resembling- those of 



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the resin-worker, texanum, here to be described. 1 



That Anthidium presents the two types of nest construction 

 in both the Old and the New World shows these to be very 

 ancient habits whose divergence occurred at an indefinitely re- 

 mote period. 



While collecting insects in January, on the south side of the 

 Colorado River, a few miles west of Austin (Texas), at an altitude 

 of about eight hundred feet, a nest of what proved to be Anthidium 

 texanuni was found. 



This structure was fastened to a branch of cedar (Jnnipents 

 virginianus Linn.) about eight feet from the ground. In appear- 

 ance it was like a small rounded conglomerate with a greatest 



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diameter of twenty-three, and a least of eighteen millimeters. 

 This curious nest consisted of small pebbles of limestone, from 

 one to three millimeters in thickness, securely cemented together 

 with an amber-colored resin, presumably derived from the cedars. 

 Its weight after the bees had transformed was five grammes. 



In this mass were six pupal cells. They consisted of a tough, 

 chestnut-brown membrane, more or less transparent so that the 

 pupae within could be seen. They were four and one half mil- 

 limeters in diameter, about ten millimeters deep, with a rounded 

 bottom, flat top, and slightly narrowed in width above. The flat 

 top consisted of tougher material, in large part spun in concentric 

 rings around a whitish, conspicuous mammilla. This projection, 

 which is characteristic of Anthidium, contained a central hole, 

 and canal to the interior. 



1 In the description of eonsimile, Dr. Davidson did not state of what material the 

 cement was composed. Since then he has informed me that the species builds at 

 times miles from any pines, so that then, at least, other plants probably furnish the 

 resin. Another species, which unfortunately was not identified, was found building 

 in pine resins on San Jacinto Mt. 



