38 PROCEEDINGS OF THE ACADEMY OF [1887. 



February 1. 



The President, Dr. Joseph Leidy, in the chair. 



Twenty-two persons present. 



Papers under the following titles were presented for publication ; 



"On the Cretaceous Formations of Texas, and their reations to 



those of other portions of North America," by Charles A. White. 



"On Zinc Manganese Asbestos," by George A. Koenig, Ph. D. 



Parasite of a Bat. Dr. Leidy remarked that it was a common 

 opinion among country people that swallows and bats were 

 infested with bed-bugs and often introduced them into houses. 

 He had convinced himself that the Ciniex infesting the cliff- 

 swallow Avas a different species from the bed-bug.^ He had 

 repeatedly examined bats without finding Ciniex. On one of 

 two small bats, from Panama Bay, presented this evening by 

 Dr. Wra. H. Jones, he found two singular insects, Avhich appear 

 to be the Polyctenes fumarius, described by Prof Westwood from 

 a bat of Jamaica. They are about half of the size given for the 

 species, but otherwise appear to agree in all respects. It has 

 four jointed antennae, with the first pair of limbs short and the 

 other pair long. The insect has distinct hemiclytra. 



On a Peculiar Form of Molybdenite. Dr. Geo. A. Koenig 

 called attention to a specimen of Molybdenite from the German- 

 town quarries, presented by Mr. Thomas Meehan. The Molyb- 

 denite forms a perfect cylinder, 2 inches long ])y ^ inch 

 diameter. It shows a lamellar structure, but the leaves are 

 twisted and felted together. Owing to the remarkable shape the 

 speaker had supposed the substance to be graphite and placed 

 by some persons quarrymen in a 2 inch drill-hole, ramming it 

 down tightly. Blowpipe tests, however, show the substance to 

 be Molybdenite. In the opeii tube a peculiar odor Avas noticed 

 not quite like that of Selenium but near it, and it was believed 

 to be desirable that a quantitative analysis should be made. 



February 8. 

 Mr Thomas Meehan, Vice- President, in the chair. 



Fourteen persons present. 



A paper entitled "On Invertebrates from the Eocene of Mis- 

 sissippi and Alabama," by Otto Meyer, was presented for pub- 

 lication. 



The following were ordered to be printed. 



1 Proc. 1877, 284. 



