518 NOTES ON LACHNOSTERNA. 



is said to have the pygidiam longer than wide. In our most typical 

 specimen careful measurement shows that it is about one-fifth wider 

 than Ion*;, and about the same as in ciliata. Finally the sexual struct- 

 ures are identical throughout the entire series, and, as has been hinted, 

 partake very decidedly of the rugosa type — the female with the devel- 

 oped pubic process, the males with very strongly dissimilar claspers. 



66. L. aemula Horn. 



Two male specimens from Florida, given by Mr. Schwarz, are in the 

 Museum collection. Mr. Schwarz collected the specimens at Haulover, 

 Fla., March 11-13, and states that they fly shortly before sunrise, in- 

 stead of at dusk and early evening, as do most of the other species. 

 The impression on the last ventral segment of the male is very variably 

 distinct, sometimes very deep, with a marked conic elevation each side, 

 sometimes so faint and vague, that it is almost impossible to say whether 

 the specimen is a male or a female. 



With this species begins again the series of forms in which the geni- 

 tal organs vary in the direction of simplicity. The claspers of the male 

 are symmetrical, and are united in front. The female was studied, but 

 in some way the preparation was mislaid and no drawing made. My 

 recollection is that it resembled rather closely the arcta type. 



67. L. arcta Horn. 



Not in the Museum collection. The female only is known, and I owe 

 to Dr. Horn an opportunity to study that sex. The superior plates are 

 distinct, but are united medially, and form a pseudo pubic process well 

 studded with short hair. 



68. L. crenulata Froehl. 



Numerous specimens, male and female, are in the collection. New 

 York, New Jersey, 13 5, 9 (coll. J. B. S.); Texas (coll. C. V. R., J. 

 B. S.), 2 5,19; Iowa (coll. C. V. R.), 1 $ ; central Missouri, May, 3 8 ; 

 northern Illinois, 2 S ; Alabama, May 10, 3 9 ; Tennessee, 1 9 (all coll. C. 

 V. R.). Mr. Ulke also has it from Florida, Nebraska, aud Dakota. For 

 dates of captures in the District, see the introductory remarks. Mr. 

 Schwarz collected it in Kentucky April 10; in Michigan (Lake St. 

 Clair, Detroit, Port Huron) in June. These localities indicate a wider 

 distribution than that given by Dr. Horn, and it has probably as wide 

 a range as any of the species. I have collected the species myself on 

 blackberry early in the evening, taking them by the dozens. Curiously 

 enough, during the collecting at Washington not a single specimen was 

 seen on that plant, though I returned, again and again to the search. 



In the series before rue the males average larger throughout than the 

 females, though they are not so robust. As a rule, the females are 

 darker, nearly black in some cases; the hair is also longer and coarser 

 than the males, and the specimens thus show considerable variation. 

 In some forms the legs and ground color of elytra are black, and this 

 form looked distinct at first, but I could not discover any differences. 



