294 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.45. 



as long, sides rather regularly arcuate, apex and base subequal, front 

 margin a little arcuately prominent at middle, base nearly straight, 

 anterior angles similar to those of the head, posterior angles obtuse, 

 surface of disk not very closely sculptured with irregularly placed 

 distinct rounded punctures which beconle smaller (or less well pre- 

 served) at the sides and anteriorly. Scutellum small, subtriangular. 

 Elytra incomplete along the margins and with the apices broken off 

 but with distinct sculpture in the form of regular striae (eight of which 

 show on the better side), sharp and well impressed, the striae with 

 regular rounded punctures separated by not much more than their 

 own diameters. Interspaces broad, impunctate. Legs wanting. 

 Length, as preserved, 6.10 mm., actual length in Ufe probably about 

 6.25 mm. Width across humeri at most prominent part, 2.60 mm. 



Type.— C&t. No. 59655, U.S.N.M. * 



One specimen which is larger than Atsenius patescens and differs 

 from it in sculpture. Since the fossil is in reverse, the striae and 

 punctures described above are represented by ridges and granules. 

 It is easily separable from the other known Florissant species by the 

 characters given. 



Genus MACRODACTYLUS Latreille. 

 MACRODACTYLUS PLUTO Wickham. 



Two specimens are contained in the collection, one of which allows 

 us to supplement the observations made upon the type by display of 

 the left antenna. This organ is composed, as far as can be made out 

 in the somewhat indistinct preservation of the articulations, of seven 

 joints, besides the club, the scape large, the stem-joints subequal in 

 length excepting the third which is rather longer. The club is not 

 spread. 



Cat. No. 59656, U.S.N.M. 



Genus DIPLOTAXIS Kirby. 



DIPLOTAXIS AURORA, new species. 

 Plate 25, fig. 2. 



Represented by an elytron about the size of that of the recent 

 D. hrevicollis LeConte, which occurs in the same general region. 

 The punctuation is fairly coarse for this genus, more so than m the 

 species cited, the punctures moderately closely placed and regular, 

 slightly smaller toward the apex. Besides the smooth sutural 

 margin, the elytron is marked with four double series of regular 

 punctures, inclosing as many smooth longitudinal lines, as in most 

 recent species of Diplotaxis. Length of elytron, 9.50 mm.; greatest 

 breadth of same, 4 mm. 



Type.— C&t. No. 59657, U.S.N.M. 



