March, 1919.] Dawson: New Species of Serica. 37 



sparsely so on the disk where the punctures are separated by one to three or 

 four times their own diameters, and more closely so toward the sides where 

 the average distance between the punctures about equals their own diam- 

 eters; an oblique, shallow impression before the basal angles. The pronotal 

 measurements are as follows : Width through the posterior angles, 43 ; width 

 through the anterior angles, 28 ; length on the median line, 22. Scutellum 

 coarsely punctured, the punctures crowded to the sides, leaving the median 

 line and apex impunctate ; length, 10; width, 10. 



Elytra strongly furrowed, almost exactly as in 6". cucullata, with the 

 usual coarse, dense puncturation of the sulci, the punctures showing a tend- 

 ency to coalesce laterally and to be arranged in three to four confused rows 

 in each sulcus ; costae rounded, bearing only an occasional puncture. Length 

 of elytra, 74; greatest width, 55. 



Posterior coxal plates coarsely and closely punctured ; remainder of ven- 

 tral surface with punctures finer and somewhat less densely placed. Fourth 

 sternite often more or less impressed at the middle, sometimes showing a 

 fine longitudinal line through the vaguely defined impression. Sternites with- 

 out the usual rows of semi-erect setae. Median impressed line of meta- 

 sternum with a closely approximated and posteriorly slightly divergent line 

 of small, confluent punctures on each side, laterad of these lines a row of 

 setigerous punctures. 



Length of genital armature of male, 3 mm. (PI. VIII) ; armature with an 

 unusually heavy stalk in proportion to the diminutive claspers. 



5- Antennal club measuring 8 instead of 10.5, as in the male; under line 

 of abdomen evenly convex ; and sixth sternite less emarginate at the middle 

 of its apical margin than in the male. 



Type: 6*. Ithaca, New York, April 14, 1915. 



Allotype: $. Ithaca, New York. May 5, 1915. 



Paratypes : 5 d 1 . 



New York, Ithaca 2 c?. 

 New Hampshire, Three Mile Island 3 c?. 

 Elusa differs from 5". cucullata by having- the clypeus some- 

 what more polished, and distinctly more sparsely punctured espe- 

 cially along the suture ; by the less depressed discal area with 

 the tumidity more limited behind and its crest more anterior in 

 position, and the clypeal incisure less pronounced and distinctly 

 more acute at the bottom. The pronotum of clusa is slightly 

 more convex, with the sides less parallel behind and less sud- 

 denly and strongly convergent in front. Altogether the resem- 

 blances of the two species are so remarkable, and the differences 

 so much more like individual variation than specific characters, 

 that one would ordinarily refuse to accept elusa as a valid species 



