34 



CALIFORNIA ACADEMY OF SCIENCES. 



Third joint of the maxillary palpi 

 gradually aud rather strongly dilated 

 toward the apex which is truncate; 

 fourth small, slender and subulate. 



Labial palpi short wdth the two ba- 

 sal joints sub -cylindrical, the second 

 a little longer than the first; the 

 third small, slender, acuminate. 



Third joint long and slender, rather 

 feebly dilated, cbconical; fourth 

 short, sligh 1 1}^ oblique, conical, acute- 

 ly pointed, nearly as wide at base as 

 the apex of the third and received 

 partly within it. 



Labial palpi slender, first joint 

 longer than wide, about one-half as 

 long as the second, which is slender 

 and more or less dilated at the apex; 

 third conical, very slender, acute, 

 much narrower at base than the apex 

 of the second. 

 Paraglossffi acuminate. Paraglossas elliptically rounded at 



tip. 

 Antennae having the second and Antennae with the second joint 



third joints sub-equal. distinctly shorter than the third. 



There are also differences in the structure of the abdomen, and in the rela- 

 tive sizes of the segments. 



Except in the characters given above, the two genera are 

 somewhat similar. In applying these to the entire group of 

 North American species, it is easily seen that the antennal 

 structure is not entirely constant, there being a few species 

 in which the second and third joints are nearl}^ equal in 

 length. The components of a very limited group of small 

 species containing pusillum, lepidum, etc., have the fourth 

 joint of the maxillary palpi small, acicular and not conicah, 

 and those should x:)robably be referred to a closely-allied 

 genus or to a sub-ganus; all the others have the fourth joint 

 conical and pointed, although varying greatly in thickness 

 at the base', all being, however, variations of one common 

 type, which is the conical and acutely pointed. Dr. Sharp 



J LeConte-Proc. Amer. Phil. Soc. XVII, 1878, p. 392. 



'^ The two species, convergens and parallelum, described by me (Cont. II, 

 pj). 129-131), aud very erroneously united by Dr. Horn (Ent. Amer. I, p. 109) 

 under the head of an entirely distinct B\)ec\e^—jloridanum — serve as a good 

 illustration of this variability of the fourth joint, this being conical and very 

 narrow, small and almost acicular in convergent, and scarcely longer than 

 wide, being strongly conical, flattened and almost as broad at base as the 

 apex of the third in parallelum. Having here incidentally made a correction 



