SCIENCE. 



[N. S. Vol. XII. No. 308. 



M. W. Lyon presented some ' Notes on the 

 Zoology of Venezuela,' stating that he spent 

 the months of July and August in that country 

 in company with Lieut. Wirt Robinson, collect- 

 ing zoological material, especially the mam 

 mals. On the way down one day was spent at 

 the interesting island of Cura§ao, a few miles 

 from the South American mainland. The 

 mammal fauna of this dry and rather barren 

 island consisted of several species of bats and a 

 rabbit. Of the former eight are known to be 

 peculiar, but related to the mainland forms, 

 although one genus, Leptonycteris, has never 

 been taken nearer than Central America. We 

 are indebted to Mr. Guthrie, in the United 

 States Weather Bureau Service, for our knowl- 

 edge of Curajaoan l^ats. 



On the continent, collecting was confined 

 to the vicinity of La Guaira, at the base of 

 the extensive range of mountains that border 

 the northern coast of South America. The 

 first few hundred feet of hills about La Guaira 

 are remarkably dry and covered with scrubby 

 trees and bushes, agaves and post-cactuses, but 

 at higher elevations where the moisture is 

 greater is an abundant growth of tropical trees, 

 shrubs and vines. The fauna of the dry region 

 is quite different from that higher up, and con- 

 sists principally of certain species of birds and 

 lizards. Mammals, as well as more or less 

 characteristic birds and reptiles, are apparently 

 conlined to the better wooded regions, or in the 

 narrow valleys that the mountain brooks make 

 on their way to the sea. There are no rivers in 

 the neighborhood. Diligent trapping does not 

 result in the numerous small mammals, as in tem- 

 perate regions or certain places in the tropics. 

 Bats are abundant in species and individuals, 

 and may be found roosting in dense trees, in 

 houses, or in the few small so-called caves in the 

 region. Among the more interesting ones are 

 disc-bats, of the genus Thyroptera, with a suck- 

 ing disc near each wrist and ankle joint, by 

 means of which it can adhere to and move over 

 smooth surfaces as glass, in the manner of 

 a fly, and the vampire, a moderately sized bat 

 with a special dentition and alimentary canal 

 for drawing blood from animals and digesting 

 it. The native or spiny rat, Loncheres, while 

 belonging to an entirely different section of the 



rodents, shows a striking external resemblance 

 to the house rats found about the towns and 

 brought in with the advent of the Europeans. 

 Several other rodents occur and four species of 

 opossums are found, including one of shrew- 

 like form and habits, of the genus Peramys. 



F. A. Lucas spoke of ' The Deposit of Masto- 

 don Bones at Kimmswick, Missouri,' saying that 

 this extraordinary aggregation of bones and 

 tusks represented hundreds of individuals of all 

 ages and sizes. But a small portion of the deposit 

 had as yet been worked, but from this had been 

 obtained teeth and bones representing between 

 two hundred and three hundred animals. The 

 full paper will appear in Science. 



F. A. Ltjcas. 



DISCUSSION AND CORRESPONDENCE. 



THE RELATION OF THE NORTH AMERICAN 

 FLORA TO THAT OF SOUTH AMERICA. 



To THE Editor of Science : In the inter- 

 esting article by Professor Bray on the relations 

 of the North American Flora to that of South 

 America, in your issue of November 9th (pp. 

 10-11), there are some geological assumptions 

 which are so at variance with the information 

 now attainable that it seems well to call atten- 

 tion to them. It is true that most of them are 

 of ancient date and found more or less accepted 

 in the literature, and that their erroneous char- 

 acter does not materially affect Professor Bray's 

 botanical conclusions ; moreover, the present 

 state of our knowledge has been set forth in the 

 annotations to a table of our Tertiary horizons 

 which appeared in the 18th Anuual Report, U. 

 S. Geological Survey, Part II, pp. 323-348, 

 1898. Nevertheless, they are so confidently 

 stated by Professor Bray that it is quite likely 

 that they may be accepted by botanical stu- 

 dents and others not especially conversant with 

 geology, and prove less innocuous than in the 

 present case. 



In the first place. Professor Bray has been 

 misled by the long continued practice of authors 

 in referring the basal Middle Oligocene of Cen- 

 tral America and the West Indies to the Mio- 

 cene. It was during this period that Central 

 America formed a series of islands and the 

 lagoon islets of south Florida first appeared 

 above the sea. During the Miocene, however, 



