512 Wisconsin Academy of Sciences, Arts, and Letters, 
name for the group. Still later^ Mr. Mathews returned to the 
subject and divided the genus OcJithodromns of Sharpe and of 
authors into five genera, by which arrangement the several 
species bore the following names, the numbers here prefixed 
corresponding to those of the species in Sharpe’s genus OcJitho- 
dromus: 
1. Pluviorliynchus ohscnrus. 
4. Oclitliodromus (or Pagolla) wilsonius. 
3. OcMhodromus (or Pagolla) wilsonius. 
5. Cirrepidesmus mongolus. 
2. Cirrepidesmus hicinctus. 
6. Cirrepidesmus atrifrons ( = pym'Jiotliorax Wagler). 
7. Eupoda (or Eupodella) asiatica. 
8. Eupoda (or Eupodella) verda. 
In the generic designations of two other species— Podasocys 
montanus (Townsend) and Charadrius liiaticula Linnaeus— 
which Mr. Mathews considered 'in the same connection, he 
made no alteration. His generic treatment of these birds was 
somewhat brief, but indicated plainly the need for recognizing 
a number of generic groups in place of the single one currently 
in use. A more detailed comparison of the various species in¬ 
volved, based on proportions obtained by actual measurements, 
which the present writer has made, shows that several changes 
from Mr. Mathews’ arrangement seem necessary, the nature 
of which will be evident from the discussion in the ensuing 
pages. In addition to the species of Oc}it}iodro7nus, the genus 
Charadrius Linnaeus (type, Charadrius hiaticula) is added for 
comparison. 
The 8 species of plovers comprising Sharpe’s genus Ochtho- 
dromus exhibit remarkable structural variations, and it is sur¬ 
prising that they have so long remained in a single genus. To 
ignore these differences as generic distinctions would be mani¬ 
festly to obscure the relationships of the species; but as no two 
forms are exactly alike in these respects, it becomes a matter of 
determining the constancy and relative importance of these 
differences as generic characters. The structural differential 
characters of value among these plovers consist almost wholly in 
® Birds Australia, III, pt. 1, April 2, 1913, pp. 81-84. 
