316 SPECIES OF COELUS (COLEOPTERA; TENEBRIONDAe) 



of the material according to the variation of morphological pecu- 

 liarities, in order to find definite characters by which to define the 

 different forms to be recognized as taxonomic grades, and to avoid 

 the use of unnecessary and impractical qualifying terms. 



As a result of this study the following characters have been 

 found of definite value : Punctuation of labrum, degree of episto- 

 mal sinuation, degree of transverse impression of the front and 

 degree of abruptness with which the base of the epistoma arises 

 from the frontal suture, punctuation of the pronotum, shape and 

 sculpturing of the mentum and degree and character of the sculp- 

 turing of the prosternum, especially that on the process. The 

 following facts also were determined: 



Color is without taxonomic value. Paleness means immaturity 

 or retarded or inhibited pigmentation and is purely physiological 

 and environmental. Large series of Coelus glohosus taken in 

 February from sand dunes at Ocean Beach, San Diego County, 

 were entirely testaceous to castaneous; later in the season speci- 

 mens from the same dunes were rufo-piceous or nigro-piceous, at 

 other times black without exception. Occasional pale specimens 

 taken among others entirely dark simply implies sporadic develop- 

 ment after the main broods have appeared. 



Form is equally without taxonomic value. In large series of 

 nearly all grades, when not founded on form alone, variations in 

 body form are abundant. The shape varies from oblong-oval, 

 more or less broad, to somewhat elongate oblong-oval, or ellipti- 

 cal. This fact can readily be appreciated if the individuals of a 

 species or race are arranged in a block system. Such an arrange- 

 ment will show that males of Coelus ciliatus, for instance, may be 

 elongate-oval or broader and oblong with all degrees of transition 

 between the extremes, other characters being identical in the 

 series. 



Unusual development in size is of some value, as in Coelus 

 grossus and its form saginatus, and smallness, in part at least, as in 

 Coelus dehilis. 



Elytral inflation is a characteristic of Coelus globosus and its 

 races. As a rule the males in each species are considerably less 

 convex than are the females. 



