Casey — A Revision of the American Paederini. 113 



wider than the pro-thorax but only very slightly longer, strongly though 

 not very coarsely, moderately sparsely punctate, distinctly impressed 

 along the suture; abdomen parallel, straight at the sides, distinctly nar- 

 rower than the elytra. Male with the third and fourth ventrals just 

 visibly impressed along the middle; fifth with a very deep elongate- 

 oval, glabrous impression, not attaining the base, the apex feebly sin- 

 uate at the middle; sixth not impressed, transversely, rectilinearly trun- 

 cate at tip, with a small and acutely triangular notch, only slightly deeper 

 than wide and an eighth or ninth as wide as the apex; female not at 

 hand. Length 4.0 mm. ; width 0.8 mm. Massachusetts (Lowell), — Mr. 



F. Blanchard ; [Florida — LeConte] nitidulus Lee. 



Body colored as in the preceding, the elytra pale testaceous throughout, 

 except a piceous-black cloud toward the suture and not quite extending 

 to the apex; head nearly as in nitidulus throughout, the antennae more 

 slender, with the medial joints fully one-half longer than wide; pro- 

 thorax but slightly elongate, much wider than the head, a little broader 

 and shorter than in the preceding species, parallel and feebly arcuate 

 at the sides, the strong punctures rather less sparse ; elytra small and 

 depressed, not as long as wide, very slightly wider than the prothorax 

 and much shorter, the sides diverging from the base, the punctures 

 rather fine but strong, somewhat sparse; abdomen parallel and straight 

 at the sides, fully as wide as the elytral apex, dull in lustre and densely 

 punctulateas in the preceding species. Male with the third ventral un- 

 modified, the fourth very feebly impressed near the apex only, the fifth 

 with a small and very deep subglabrous pit, rounded in outline, ex- 

 tending from a little before the middle to the apex, the latter feebly 

 sinuato-truncate ; sixth with an acutely angulate triangular incisure, 

 deeper than wide, larger and deeper than in nitidulus and a seventh or 

 eighth as wide as the apex, the latter anteriorly and outwardly truncate 

 at each side; female not known. Length 4.5 mm.; width 0.75 mm. 

 Massachusetts (Lowell), — Mr. Blanchard parvipennis n. sp. 



The difference in general facies between the large-winged 

 and short-winged species in all these genera of the Lathrobia 

 being so pronounced, with most other characters so similar, 

 has suggested the presence of dimorphism, but I have been 

 unable to prove this in any one instance, and, indeed, the 

 only useful evidence will be that gained by actual observation 

 of the life history of the species. The normal sexual differ- 

 ences in the elytra are not great, although nearly always 

 observable, the elytra of the female being a little larger than 

 those of the male, but, as can be seen in this genus, as well as 

 in Tetartopeus lacustris, the presence of short winged forms, 

 if not indicative of specific difference, must be due to 

 perfectly asexual dimorphism, — a matter impossible to prove 

 without careful biological study. 



