1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 99 



pared were iu equally bad feather. The National Museum having 

 subsequently acquired a much better series of P. arizonw, a second com- 

 parison of the Texas bird has been made, the result being quite unex- 

 pected, since it proves to be identical with a Mexican form, apparently 

 quite distinct from P. arizonce, and to which the name Coturniculus mexi- 

 canus was given by Mr. George N. Lawrence, in 18G7. The latter name 

 was in the History of North American Birds (fi, p. 38, foot-note) referred 

 as a synonym to Peuccea hotter ii Scl., of Eastern Mexico (Orizaba), a dis- 

 position which I am now convinced was erroneous. A second Mexican 

 example of P. mexicana has been sent to the National Museum by Prof. 

 A. Duges, from Guanajuato, and proves to be so closely similar to Dr. 

 Merrill's specimen, and also to the type of " Coturniculus mexicanus^ 

 as to leave no doubt as to their identity. 

 The synonymy of the species is as follows : 



-T-Peucaea mexicana (Lawr.). 



Coturniculus mexicanus Lawr., Ann. Lye. N. Y., viii, 1867, 474 (mountains of Co- 



lima). 

 Peuccea cestivais var. liotterii B. B. & R.,Hist. N. Am. B.,ii, 1874, 38, foot-note (part). 



(Nee Zonotricliia hotterii Scl., 1857.) 

 Peuccea arizonw RiDGW. and Merrill, Pr. U. S. Nat. Mus., vol. i, 1878, 127 (near 



Fort Brown, Tex.). Nee Peuccea cestivalis var. arizonce Ridgw.,1874.) 

 Peuccea mexicana Rldgw., M. S. 



ON DEPOSITS OP VOLCANIC DUST AND SAND IN SOUTHWEST- 

 ERN NEBRASKA. 



By CEORQE P. VIERRIL.!^. 



In January, 1885, there were received at the National Museum two 

 samples of a fine sharp dust marked " silicic acid," and which were 

 supposed by the sender, Mr. Henry Zahu, of Plattsmouth, Nebraska, to 

 be hot spring or geyser deposits, and were therefore called by him 

 " Geyserite.'' Mr. Zahn states that the dust is found in small deposits 

 in Western Kansas, Nebraska, eastern Colorado, and Wyoming. Con- 

 cerning the two samples sent he writes : " The deposit of the gray sam- 

 ple is located in Furnas County, southwestern Nebraska, nearly 2 miles 

 south of the Republican River, on sections 8 and 9, township 3 north, 

 range 21 west of the sixth principal meridian. The white sample is 

 from Harlan County, adjoining Furnas on the east, sections 10 and 11, 

 township 2 north, range 20 west, a mile south of the Republican River. 

 The deposits of this material occur mostly in this State, on the Repub- 

 lican River, extending into Kansas. By taking a mai) you will see 

 numerous creeks flowing from the north and south and forming this 

 river. Into the larger creeks flow numerous rivulets. On these stream- 

 lets we find the deposits, always on the east side, excej)ting the de- 

 posits in Harlan County, which I find on both sides of the ravine. The 

 deposits occur from Guide Rock west to State line. * * * The de- 



