FRANK E. BLAISDELL, SR. 329 



is the very coarsely punctured prosternum in front of the coxae. 

 The punctures are more or less rounded, rather distinctly sep- 

 arated and impressed and there is a tendency to rugoseness. 

 The surface is rather glossy in the series examined. The degree 

 of constriction of the prosternal process is not staple and cannot 

 be used in defining species in a genus like Coelus. Here is a 

 parallel with Coniontis where the individuals of a specific ag- 

 gregate vary greatly in form. Arenarius and sternalis are mem- 

 bers of the ciliatus group, as evidenced by the epistomal base and 

 mentum. 



The sexes are of the usual form as in arenarius, the females are 

 usually more or less narrower than the males. 



Measurements. — Length, 6.5-8.6 mm.; width, 4.2-4.85 mm. 



Type locality. — Santa Barbara, California. 



Coelus arenarius variety latus Casey 



A definition of this variety must also include amplicollis. In 

 a series they are inseparable. 



Form stout, oblong to subquadrate. Pronolum closely, more or less coarsely 

 punctate, punctures evenly distributed; sides distinctly declivo-explanate, 

 but this character varies greatly in degree. 



Proslemum coarsely and more or less confluently punctate, subrugose. 



Male. — Broader and the sides of the pronotum are usually more strongly 

 declivo-explanate. 



Female. — Rather narrower, sides of the pronotum are less strongly declivo- 

 explanate. 



Measurements. — Length, 4.9-7.6 nun.; width, .3-.5 mm. 



It is often difficult to tell the sex by form alone. The name 

 arnplicollis has been given to the more common form, but on ac- 

 count of priority it must give way to latus Case^^ The type 

 locality for both is San Diego, California. Amplicollis is found 

 abundantly with globosus, and latus Casey occurs as an extreme 

 form of the former. A large series has been studied. These 

 specimens were collected by the author in February and April, in 

 1890 and 1891, and by Mr. Van Duzee in August, 1916, at the 

 type locality. 



Casey in his third group of species founded on the degree of 

 epistomal sinuation, divides those forms with a very feeble sinua- 

 tion into two sections, based on the distribution of pronotal punc- 

 tures, which, in a large series, is a very unstable and evanescent 



TRANS. AM. ENT. SOC, XLV. 



