I STUDIES IN OMUS AND CICINDELA. 



Having recently received a considerable series of Omus and many 

 interesting new forms of Cicindela, it seems desirable to draw up a 

 short paper on the subject and the opportunity is taken to give a 

 renewed systematic study of the genus Omus, which may aid in 

 forming a more exact and comprehensive idea of the relative degrees 

 of relationship of its many rather confusing species and subspecies. 



Omus Esch. 



This genus, as known at present, may be divided into three 

 passably well defined subgenera as follows: 



Elytra oval; lateral margins of the pronotum acute and without setae. .2 



Elytra subcylindric, the lateral thoracic margins not so acute and having 

 erect setae 3 



2 Elytra with numerous very large foveae, which are disposed without 

 order among the smaller punctures common to all the species of the 

 genus; median line of the pronotum dilated and foveiform at the 

 middle. [Type and only known species Omus dejeani Reiche]. 



Megomus 



Elytra with very small and sparse foveae mingled with the punctures; 

 median stria of the pronotum never so dilated centrally; coloration 

 deep black to slightly brownish, apparently never metallic. [Type 

 Omus calif ornicus Esch.] Omus 



3 Elytra punctured and with small sparse foveae nearly as in Omus; 

 colors generally submetallic. [Type and only known species Omus 

 siibmetallicus G. H. Horn] Leptomus 



It is not necessary to refer more particularly to dejeani and 

 siibmetallicus just now and the present study will be limited to the 

 subgenus Omus as defined above. 



Subgenus Omus Esch. 



Observing critically the very numerous taxonomic forms of this 

 subgenus, it becomes easy to recognize seven well defined groups 

 as follows: 



Antennae distinctly shorter in the female than in the male; prothorax 

 relatively narrow, feebly sculptured, deeply declivous at the sides; 

 elytra having a tendency to be broadest behind the middle. Northern 

 coast regions Group I 



T. L. Casey, Mem. Col. V, Oct. 1914. 



