The Treasurer presented a bill for the printing of No. i of vol. 

 III. of the Transactions, amounting to $943.63, which was or- 

 dered to be paid. 



Mr. Hobart presented a photograph of a large skull of the Musk 

 Ox which had been found in a well twenty feet below the surface 

 of the ground, about ten miles west of Sauk City. Sauk Co., Wis., 

 said to be the only specimen of the kind ever found in the limits 

 of the U. States. On comparison with the skull of the fossil ox 

 (Bos cavifrons) in our museum, from alluvial deposits in Chou- 

 teau's Pond, in St. Louis, it was found that but very slight simi- 

 larity existed between them. 



Mr. Riley exhibited a specimen of a huge and curious spider 

 (Nephila plumipes Koch) which had been sent to Dr. Engelmann 

 from South Carolina, and remarked that it was peculiar from the 

 diminutive size of the male as compared with the female, the 

 body of the former being but one-quarter of an inch long, while 

 that of the latter was nearly an inch longer. The female has also 

 brushes of stiff hairs upon her legs, and loses no opportunity of 

 displaying her superiority of size and strength by devouring her 

 mate whenever she gets a chance. The silk of this spider may 

 be drawn out of the abdomen in one continuous thread, and is 

 quite strong and beautiful. Prof. B. G. Wilder had once reeled 

 upwards of two miles of it. 



Mr. Riley also explained the peculiarities of the Mexican 

 honey-ant, presented by Dr. Engelmann. It was the Myrmecocys- 

 tus mexicanus of Westwood (Entomb ii. p. 225, note). The species 

 has two kinds of neuters, those with ordinary sized abdomens, 

 and those having the membrane of the abdomen much swollen 

 and distended. These last do not quit the common nest, but de- 

 vote their time entirely to the elaboration of a kind of honey, 

 which they discharge into cells made somewhat after the plan of 

 those of the common honey-bee. 



He also exhibited a plant possessing flowers of such peculia 1 * 

 structure that large Sphinx moths were often caught in them by 

 not being able to withdraw their tongues when once inserted. 

 The plant was known as the Pliysianthus albens, rarely seen in cul- 

 tivation in this country, though a very beautiful climber. 



Mr. Henry Senter was elected an associate member. 



