Platyxix.e 123 



the thoracic sides are brownish and less rounded than in melanarium 

 and that the hind angles are less rounded, from which it may be 

 inferred that they are rather sharply defined, and further that the 

 legs and antennae are blackish-brown, seem to preclude any such 

 identity. In dimensions mcerens must be rather small, if measured 

 correctly, although it was the habit of Dejean to understate, as it 

 was of LeConte to overstate, these characters; mcere^is is said to be 

 7.5 by 3.3 mm. in length and width. Its exact habitat is unknown. 



Group IV — placidiim 

 Subgenus Paragoniim nov. 



The few species of this subgeneric group resemble some forms of 

 the preceding subgenus in general characters, but the integuments 

 are thinner and the pronotal foveae are large, concave and extend 

 to the sides, the strongly reflexed margin forming the outer wall 

 of the foveae, a structure wholly different from anything observable 

 in Melanagonum. There are three verj' distinctly differentiated 

 species and some minor taxonomic forms as follows: 



Dorsal punctures of the elytra very fine, five in number, rarely four or 

 six. Body oblong, moderately convex, polished black in the male, 

 the female elytra alutaceous to subopaque; anterior parts some- 

 times faintly greenish; legs piceo-rufous; head rather small, with 

 well developed and rather prominent eyes, the impressions short 

 but deep and with finer oblique posterior prolongation; antennae 

 slender, half as long as the body or nearly, blackish-piceous, the 

 basal joint pale, the third and fourth equal; prothorax a fourth to 

 third wider than long, the sides parallel, evenly and rather strongly 

 rounded and strongly reflexed, especially toward base, the edge very 

 thin; angles broadly obtuse and rounded; base rounded laterally, 

 distinctly wider than the deeply sinuate apex; anterior impression 

 rather evident, the stria fine; foveae large, concave, feebly rugulose, 

 not prolonged anteriorly; elytra nearly three-fifths longer than 

 wide, not quite one-half wider than the prothorax, very gradually 

 rounded behind, with feeble sinus; striae fine, smooth; intervals 

 flat or nearly so, the three anterior punctures at the third, the two 

 posterior at the second, stria; tarsi slender, the external sulcus 

 deep, the anterior distinctly dilated in the male; hind wings well 

 developed. Length (c^ 9) 7.5-8.8 mm.; width 2.9-3.4 ni"i- 

 Rhode Island to Lake Superior, Kansas, Colorado and New Mexico. 



Very abundant. [Ag. morosum Dej.] placidum Say 



A — Closely related to placidum but a little larger and notably broader, 

 the female elytra more densely opaque as a rule and more obtusely 

 rounded at apex; hind body and met-episterna relatively less 



