THE GENUS DENDROCTONUS. 5 



SYNONYMY. 



The following species were included, all but two of which were 

 subsequently referred by Eichhoff (1864) to other genera: 



Bostrichus micans Kugelann = Dendroctonus micans (Kugelann) . 



(Type -of genus.) 



Scolytus terebrans Olivier = Dendroctonus terebrans (Olivier). 

 Dermestes piniperda Linnaeus = Myelophilus piniperda (Lin- 

 naeus). 



II)/lurgus minor Hartig = Myelophilus minor (Hartig). 

 Ilylesinus minimus Fabricius = Carphoborus minimus (Fabri- 

 cius.) 



BE VISIONAL NOTES. 



The generic characters mentioned by Erichson in the original 

 description are recognized in the type and other species except that 

 the maxillary palpi are not 4-jointed. The first or basal joint has a 

 basal ring or outward curved basal margin for the attachment of the 

 membrane connecting the joint with the palpiger. This might have 

 been mistaken for the "very short first joint" referred to, but it is 

 evident that this or any other structure does not represent such a basal 

 joint. In the type species the first joint of the club is equal to the 

 others, but ranges from shorter to longer in the other species. 



Le Conte's added characters in his revision of 1868 and 1876 are 

 generally correct, except that the antennal club is not always concave 

 on one (external) side or anterior face, the sutures are more often 

 curved than straight, and in some species only two sutures are 

 visible on one side of the club. The prosternum is sometimes flat, the 

 fifth joint of the tarsus is never longer than the others united, and the 

 ventral segments are only approximately equal in length, the last 

 one being usually as long as the two preceding combined. 



Dietz (1890) called attention to the unreliability of the sutures and 

 joints of the antennal club in dried specimens, and laid special stress 

 on the value of the epistoma in distinguishing the species. It appears, 

 however, that while the form of the epistoma is a good generic and 

 Bubdivisional character, it is of little or no value in distinguishing the 

 species. 



The additional generic characters recognized by the writer will be 

 found described under external and internal anatomy, and the char- 

 acters distinguishing the major and minor divisions will be found in the 

 synoptic tables. 



REVISED DESCRIPTION OF GENUS. 

 ANATOMICAL. 



The following discussion of anatomical details includes the imago, 

 larva, and pupa, and is based primarily on the results of original 

 dissections and anatomical investigations by the author during the 



