Mat 28, 1909] 



SCIENCE 



871 



Hence, by locating the points a, a' and a" one 

 can determine, with almost mathematical 

 precision, the land next in order to be re- 

 moved and the location of the new deposit. 

 Again, sooner or later points a and a' will 

 coincide and lines aX' and a'X" will coin- 

 cide. 



The dotted line yy' represents the manner 

 of washing since this article was first pre- 

 pared. The railroad and station at Barney 

 have been washed out and a new station has 

 been located farther to the southwest as indi- 

 cated on the chart. 



We have taken simply one section of the 

 river as an illustration; but, after studying in 

 detail a large number of these curves and 

 after studying in a general way the entire 

 river bed from Sioux City to the southern 

 border of Nebraska we believe no exception to 

 the chart can be found. In applying these 

 principles to the washings of the eastern bank 

 of the river all positions would be reversed. 



The effort to hold the channel of the river 

 under the bridges at Omaha and Nebraska 

 City has greatly influenced the recession of 

 the series of curves below each bridge. 



We may, therefore, summarize the follow- 

 ing points : 



1. That the Missouri River channel is 

 methodical in its shiftings. 



2. The location of the new channel and the 

 new deposit may be determined beforehand 

 with mathematical precision. 



3. There is a recession of the series of 

 curves down stream. 



4. The channel cuts the western bluffs at 

 more or less regular intervals. 



5. At no point does the river encroach upon 

 the eastern bluffs. H. B. Duncanson 



Nebraska State Nobmal School, 

 Pebu, Nebe. 



the proper name of the american eel 



ANGUILLA ROSTRATA (LE SUEUr) 



Through an error in recording the date of 

 publication the common American eel has 

 been given a later-bestowed technical name 

 and the author of a prior name and descrip- 

 tion has been denied the honor of first naming 

 the American species. 



In the Journal of the Academy of Natural 

 Sciences, Philadelphia, No. 5, Vol. I., p. 81, 

 C. A. Le Sueur described the common Ameri- 

 can eel under five specific names, viz. : rostrata, 

 BostoniensiSj serpentina, argentea and macro- 

 cephala, all of which he erroneously placed 

 under the genus Murwna of La Cepede. 



Several months later C. S. Eafinesque, in 

 The American Monthly Magazine and Critical 

 Review, No. II., Vol. II., p. 120, described this 

 eel under the name Anguilla chrisypa and A. 

 hlephura, and his note after the descriptions, 

 " These two species of eels appear different 

 from all the new species lately described by 

 Mr. Lesueur, under the old name of Murcena, 

 which belongs properly to a very different 

 genus without pectoral fins," led me to look 

 into the matter of the proper name for the 

 American eel. 



Eafinesque's name chrisypa has of late 

 years been applied to this eel, authors citing 

 1821 as the date of publication of the journal 

 in which Le Sueur's descriptions occur not- 

 withstanding the fact that the numbers are 

 plainly marked. No. 1, May, No. 2, June, No. 

 3, July, No. 4, August, and No. 5, September, 

 1817. From the dates and other marks on 

 these numbers it was evident that they were 

 promptly printed, but having been informed 

 that the journal had not been printed and pub- 

 lished, as dated, I addressed a note to Mr. 

 Witmer Stone, of the Philadelphia Academy 

 of Natural Sciences, and quote his courteous 

 and satisfactory reply, written March 17, 

 1909. 



My dear Mr. Bean: Such data as I have ac- 

 cumulated on dates of issue of our publications 

 relate to our Proceedings only & I had little hope 

 of solving the problem contained in your letter. 

 Fortunately I asked Mr. Wm. J. Fox our Asst. 

 Librarian if he knew of any clew and he sug- 

 gested looking in a bound volume of manuscript 

 letters from Thos. Say to Eev. J. F. Melsheimer, 

 from which he had published extracts some years 

 ago in Entomological News, as he thought there 

 was some allusion to sending parts of the Journal 

 to Melsheimer. Curiously enough the first men- 

 tion of the matter that we found was as follows, 

 in letter dated November 6, 1817, "yesterday I 

 sent you the Fifth part of the Academy's Journal 

 and tomorrow I will send you the sixth." 



