330 SPECIES OF COELUS (COLEOPTERA; TENEBRIONIDAE) 



difference. His next dichotomous division is on the form and 

 relative width of the pronotiim and elytral base. Both of these 

 characters appear to be very arbitrary indeed. By an examina- 

 tion of a considerable series collected at Redondo it was observed 

 that the individual specimens differed among themselves, as 

 regards the relative width of the pronotum and elytral base, just 

 as do the specimens taken at San Diego and referred to amplicollis, 

 and all gradations exist between the two series. The same is 

 true as regards ohscurus and scolopax. 



It is the writer's conviction founded on long and careful 

 comparison of series collected along the southern California sea- 

 coast .that other characters must be found to differentiate ob- 

 scurus and scolopax, or they must be considered as mere forms of 

 arenarius. Theoretical grading of organisms based on geogra- 

 phical position is unacceptable when intrinsic structural or stable 

 characters are wanting. Geographical position and environment 

 act more physiologically than morphologically. Why not con- 

 sider the muscular, sun-burnt and non-adipose farmer or country 

 dweller as a different species from the fairer, non-muscular and 

 adipose city dweller? 



An analysis of the arenarius complex may be attempted by 

 the following tabulation of published characters: 



Epistoma broadly and very feebly sinuate, the sinus generally sub-evenl}' 

 rounded. 



Punctures of the pronotum unequally distriliuted, leaving large areas devoid 

 of punctuation. 



Body rather broadly oblong-oval arenarius, San Pedro 



Body more narrowly elongate-elliptical. 



arenarius variety sternalis, Santa Barbara 

 Punctures of the pronotum almost evenly distributed. 



Body evenly elliptical in form; prothorax not at all wider than the elytral 

 base. 



Form rather elongate . . arenarius form obscurus, Los Angeles Count j' 

 Form relatively a little wider, .arenarius form scolopax, Heilondo 

 Body broadly oblong-oval, prothorax more .swollen basallj', and at a short 

 distance before the base, distinctly wider than the elytral base. 

 Body very stout and subquadrate. 



arenarius variety latus, San Diego 

 Body similarly stout oblong, but little longer than wide. 



arenarius form amplicollis, San Diego 



