128 Coleopterological Notices, III. 



New York ; Georgia ; Florida. 



The sexual differences appear to be exceedingly feeble. 



This species is one of the smallest of the genus, and may readily 

 be known by its extremely sparse minute punctuation, almost in- 

 visible pubescence and absence of elytral series. 



M. fraterna Say.— Journ. Ac. Phil., Ill, 1823, p. 270; laticollis Lee: 

 Pr. Am. Phil. Soc, XVII, p. 617. — Oblong-elongate, subparallel, moderately 

 convex, piceous-black, the under surface, legs and antennae slightly paler, 

 piceous to rufo-ferruginous, each elytron with a large pale oblique spot from 

 near the suture to the humerus, polished ; pubescence fine, short, not very 

 dense and not conspicuous. Head feebly convex, rather finely, sparsely and 

 somewhat unevenly punctate ; eyes moderate, separated by but slightly more 

 than twice their width ; antennae nearly one-half as long as the body, moder- 

 ately slender, the joints very feebly obconical, not distinctly narrower toward 

 apex, the intermediate about three-fourths longer than wide, third fully as 

 long as, or perhaps a little longer than, the fourth. Prothorax about three- 

 fourths wider than long, the apex feebly arcuate, scarcely two-thirds as wide 

 as the base, the latter transverse, the sinuations almost obsolete, the angles 

 slightly obtuse, not rounded ; sides broadly, very distinctly arcuate through- 

 out ; disk widest near basal third, somewhat finely, sparsely punctate, broadly 

 impressed in the middle toward base, the basal foveas very broadly impressed 

 and indefinite. Elytra a little more than three times as long as the prothorax, 

 scarcely visibly wider, rather gradually and acutely rounded behind ; disk 

 somewhat strongly, sparsely and unevenly punctate, devoid of series and 

 without impressed lines, except more or less vaguely near the suture. Under 

 surface very sparsely punctate. Length 3.9-6.0 mm. ; width 1.4-2.3 mm. 



Pennsylvania ; New York ; Canada. 



The description refers to the male which appears to be much 

 smaller and more slender than the female. In the latter sex the 

 antennae are relatively shorter and the prothorax is slightly more 

 transverse. Fraterna is more northern in its distribution than 

 haldemani. 



I think that the unique specimen described by LeConte as lati- 

 collis is simply an extreme form of the female of this species. The 

 punctuation, especially of the head, is very uneven and quite vari- 

 able in fraterna, and there seemingly exists a most perplexiug 

 plasticity in the form of the prothorax in some species — see remarks 

 under tenuis. In fact I have before me a normally punctate speci- 

 men of fraterna, in which the prothorax is somewhat dilated and 

 rather wider than the elytra, just as in the type of laticollis. 



Although Melsheimer states that his ruficornis is distinct from 

 fraterna, I am inclined to think that it is nothing more than an 



