Coleopterological Notices. 1G3 



LUCANID.E. 

 PLATYCERUS Geoff. 



A sexual character, which seems to have escaped observation, 

 exists in perhaps its greatest development in quercus. It will be 

 seen that in this species, the posterior tarsi of the female are much 

 shorter than in the male. In oregonensis the same condition holds, 

 but to a less-marked degree, and in Agassii the character completely 

 disappears, the tarsi in both male and female being very long and 

 slender, with the fourth joint twice as long as wide. The type of 

 californicus is a female, and, as the posterior tarsi are extremelv 

 short, relatively more abbreviated even than in the female of quer- 

 cus, with the fourth joint fully as wide as long, it is probable that 

 the male, also, has a shorter tarsus than Agassii, and that the 

 species is to be associated with quercus and oregonensis, rather 

 than with Agassii} 



Through the kindness of Mr. J. J. Rivers of Berkeley, California, 

 who has made the study of this genus somewhat of a specialty, I 

 have been permitted to examine a larger series than has been 

 hitherto available to me, and find that there are several species 

 similar to Agassii in having the mandibles small and inconspicu- 

 ous in the males, and the hind tarsi nearly as long as the tibia?. 

 The series alluded to affords sufficient material for a tolerably com- 

 plete study, and consists of twelve specimens of Agassii, three of 

 pacificus, and two of parvicollis. These three species may be 

 defined as follows, the characters given referring to the male only: — 



Sides of the prothorax — viewed vertically — distinctly subaiigulate. 



Pronotum finely, densely punctate ; antennal club much longer than the 

 funicle, the last joint strongly asymmetric, the longest dimension being 

 in a direction oblique to the axis of the club, and very much exceeding 

 the width ; sixth joint of funicle strongly produced anteriorly ; fifth joint 

 of hind tarsi as long as the first and second combined ; elytra equal in 

 width to the prothorax Agassii 



1 I have recently had occasion to inspect the original female type of Agassii 

 in the museum at Cambridge, Mass., and find that the specimens heretofore 

 regarded by Mr. Fuchs and myself as representing that species, were correctly 

 identified. The type, apart from its slightly paler color due to immaturity, 

 dqes not differ in the slightest degree from the average female, and the inmc- 

 tuation of the pronotum is equally dense. 



