114 THE CANADIAN ENTOMOLOGIST. 



plant, and if they do not know it, if a sample is sent to me (in bloom if so 

 found), I will be pleased to determine it. It seems to me that it is 

 desirable to have them in collections as varieties, if not species. Besides 

 color, there are two or three structural differences that appear sufficiently 

 permanent to effect this. The black thoracic spot of unipunctata is 

 elongate and divided longitudinally by a deep, acute incision ; anterior to 

 this is a transverse arcuate impression with the convexity posterior, and 

 more or less apparent ; in front of this impression the sides of the thorax 

 have the appearance of having been pinched, so that the dorsal line seems 

 somewhat roundly carinate to the thin apical margin. In ^-punctata this 

 spot is larger and more broadly oval ; in some individuals there is a very 

 shallow depression, while in others it is not observable ; anterior to this 

 the thorax is full and convex, without the compressed appearance of the 

 other, and there is no trace of the arcuate impression. 



Smycronyx griseus Lee. is often called for, though excessively abun- 

 dant everywhere, occurring in August and September on the rag-weed of 

 the fields (Ambrosia artemisicefolia). At first the elytra are clothed with 

 gray pubescence finely mottled with closely placed, minute whitish spots, 

 and the thorax has four pale vittje ; but with age all these mostly disap- 

 pear, the gray alone remaining. This is the species recognized as griseiis, 

 though the second joint of the antennae is scarcely shorter than the first, 

 and nearly twice as long as the third, not agreeing in this with Dr. Le- 

 conte's description in the Synopsis. Brachytarsus tomentos7is is often 

 found plentifully with it, and it may be well to remember that both species 

 may be beaten from the trees and bushes bordering fields in which the 

 weed grows. 



Smycronyx tychoides Lee. Is found during August with Barytychius 

 amoetms, on a variety of the great ragweed. Ambrosia integrifolia, though 

 neither are so abundant as the preceding species. While belonging to 

 different genera, it requires close inspection to separate them if rubbed, or 

 old : B. arnxnus has the sides of the thorax much rounded in posteriorly, 

 and the disk as well as that of the elytra roundly depressed from the middle 

 to base, which is much below the plane of the disks at middle : while in S. 

 tychoides the bases are nearly on the same plane, though the thorax is as 

 much rounded at the sides. The vestiture is of patterns about equally 

 divided among the individuals. The one has a common sutural stripe 

 blackish brown, the rest of the elytra being more or less rufous, and is 



