Platynin^ 131 



smooth, not very fine, sharply and deeply grooved; intervals feebly 

 convex in both sexes, the third with the usual four to five punctures; 

 anterior male tarsi difYering greatly from those of leiiis, being much 

 more slender, with the less elongate joints smooth above. Length 

 (cf 9) 5-5-6.5 mm.; width 1.8-2.2 mm. Long Island, Pennsyl- 

 vania, Indiana and northern Illinois. elongatulus Hald. 



Color black, the elytra rufo-piceous; under surface black, the epipleura 

 and legs bright rufous; size much smaller, moderately convex; 

 head slightly elongate, much narrower than the prothorax, with 

 scarcely at all prominent eyes; antennae rather thicker than usual 

 and with much shorter joints than in any of the preceding, pale 

 fllavo-ferruginous throughout, half as long as the body; prothorax 

 slightly shorter than wide, the moderately arcuate sides rather 

 narrowly but sharply reflexed, evidently a little more so at base; 

 angles broadly rounded; base and apex subequal; foveae irregularly 

 linear, broadly and rather deeply impressed; elytra smaller than 

 usual, not over one-half longer than wide, more or less obviously 

 dilated behind, three-fourths wider than the prothorax; apex 

 gradually rounded, the sinus shallow but evident; striae not very 

 fine, deeply grooved, smooth; intervals feebly convex, the third 

 with four punctures; met-episterna small, not one-half longer than 

 wide; anterior male tarsi narrowly but distinctly dilated, the 

 joints not much elongated. Length (cf 9) 5-5-6.0 mm.; width 

 2.0-2.3 mm. Lake Superior (Bayfield and Duluth).. .serenus n. sp. 



The species described above as galvestonicus is normal so far as 

 generic structure is concerned, but it differs from the more northern 

 types in the much more prominent eyes and more depressed upper 

 surface. There seem to be, a number of forms related more or less 

 closely to lutulentus, this type being peculiar in the pallid coloration 

 of the body, with very black head, which prompted LeConte to 

 place nigriceps in their vicinity in his treatment of the subfamily. 

 There is no close affinity, however, nigriceps, by antennal structure, 

 pertaining to a different generic group; it is assigned to the special 

 genus Platynomicrus above. 



Retractus, as represented by the Lake George examples above 

 described, seems to be identified correctly, although in these New 

 York specimens the upper surface is deep black throughout, the 

 elytra not evidently picescent, as intimated of the Lake Superior 

 types. Elongatulus is made a synonym of picipennis by LeConte, 

 but it differs in its smaller size, still more slender outline, paler 

 elytra and antennae and more obviously, though by no means 

 strongly, reflexed basal part of the thoracic margin; the anterior 

 male tarsi are of the usual type and not aberrant as they are in 

 lenis Dej. 



