1912 J Correspondence. • 429 



CORRESPONDENCE. 



Sclater's Contour Map of Colorado. 



Editor of 'The Auk': 



Dear Sir: — In commenting upon Sclater's excellent book on the Birds 

 of Colorado in the April number of 'The Auk,' I neglected to mention 

 his map. It is very unfortunate that he repubUshed this map, which is 

 evidently taken from Rydberg's Flora of Colorado, because it is exceedingly 

 incorrect as to contour Hnes. In a state Mke Colorado, presenting differ- 

 ences in altitude of a mile and a half, the altitudes of various localities are 

 of great importance to naturalists. Altitude is an essential element in 

 the study of the distribution of plants and animals in Colorado and of the 

 migrations of birds. In the map in question, to take a few out of many 

 examples, the contour lines give Boulder an altitude of about 2 000 feet 

 too much, Golden 2,500 feet too much, Denver 1,000 feet, Trinidad 1,000 

 feet. Meeker is placed considerably too low, etc. Fortunately a gazeteer 

 in each of the books mentioned will in part correct the faults of the map for 

 those who notice and use it instead of the map. The altitudes of most 

 of the towns of the state may also of course be obtained from the Dictionary 

 of Altitudes published by the United States Geological Survey, or the 

 Gazetteer of Colorado (Bulletin 291 of the same survey). These publica- 

 tions also give the altitudes of many other points aside from the towns. 

 Nearly all western railway folders also give the altitudes of stations along 

 their routes. The Colorado Geological Survey has almost ready for the 

 printer a new topographic map of the state, based upon data from the 

 most reliable sources, which will place the contour hnes in as nearly their 

 correct positions as can be done at present, and in those portions of the 

 state where detailed field work has been done the lines will be very accurate. 

 Consequently no naturalist need have any difficulty in most cases in ob- 

 taining altitudes, providing he is warned against using the map in Sclater's 

 book and in the Flora of Colorado. 



Junius Henderson. 



A Correction. 



Editor of 'The Auk': — 



Dear Sir: — • I find that the Index to the ' Bulletin of the Nuttall Orni- 

 thological Club ' and ' The Auk ', for the period 1876-1900 (New York, 

 1907), includes on page 72 the titles of all the contributions of the late 

 Captain John Clifford Brown, U. S. V.^ under another's name, though on 

 page 235 "Brown, J. C." is given credit for four of them which relate to 



1 See Auk' XVIII, pp. 220-221. 



