PREPARATION OF A GEOLOGIC MAP 61 
outcrop, reconnaissance, detailed, etc.), and should also describe 
the area covered by the geologic coloring. As to wording, the 
title should be as concise as possible, and grammatically correct. 
such expressions as ‘‘ Geologic map of the HVeInun OT Lu Geo- 
limestone,’ should be avoided. It is 
logic map of the 
frequently necessary to publish maps of areas which for some 
reason cannot be readily located or described in words, so that 
the title (unless made unreasonably long) cannot be made 
entirely satisfactory in regard to its geographic precision. In 
such cases at least one meridian of longitude and one parallel 
of latitude should be introduced and properly numbered, to serve 
as an aid in locating the area mapped. 
Author and date-—The name of the geologist or compiler 
should be given on the map, together with the date. So far 
as the latter is concerned, for most purposes the year will 
be sufficient; occasionally a more precise statement will be 
advantageous. This date should in every case be the date of 
completion of the manuscript map ; its date of publication will 
be fixed by other evidence. | 
Acknowledgments.— In the case of a compilation, if space be 
available, credit should be given on the map to the various 
geologists whose partial maps were utilized. If space is not 
available on the map itself, reference should be made to the 
publication in which these acknowledgments are made. Remiss- 
ness in this respect, whether intentional or not, is unpardon- 
able. Plate I of Monograph V, United States Geological Survey, 
( Copper Bearing Rocks of Lake Superior), is particularly detailed 
in its acknowledgments, despite its comparatively small size. 
Legend.— The amount of detailed information to be given in 
the legend is governed by two considerations. The first is, of 
course, the amount of space available on the map. ‘The second, 
on which sufficient stress is rarely laid, is the liability of the map 
to be separated from the text. Every convention used on the 
map must be explained in the legend; but the extent to which 
this explanation should be carried depends largely on the form 
in which the map is published. A map issued inaroll or pocket 
