HO. 1982. FOSSIL COLEOPTERA FROM FLORISSANT— WICKHAM. 285 

 Genus AGABUS Leach. 



AGABUS FLORISSANTENSIS, new species. 

 Plate 23, figs. 1, 2. 



Preserved in ventral view and much carbonized so that most of 

 the sutures and details of minute structure are lost. Form ovate, 

 sides not parallel. Line of demarcation between head and prothorax 

 not distinguishable, but the latter is broader posteriorly, as in most 

 of the species of the genus. Hind leg with the third and fourth tarsal 

 joints shorter than the second and fifth, claws rather long, curved 

 and equal. Length, 11.35 mm.; width of elytra, about the middle, 

 6.30 mm. 



Type.—Csit. No. 59632, U.S.N.M. 



One specimen. This insect is somewhat similar in form to Agabus 

 (Gaurodytes) ausiinii, but is more obtuse behind. It is also much 

 larger, equaling in size any of the specimens of A. lugens in my col- 

 lection. The generic reference seems fairly safe, the facies agrees 

 with Agabus, so do the ventral sclerites as far as shown, whUe the 

 claws are entirely unlike those of our other genera of large Dytiscids 

 to which the specimen might otherwise be presumed to belong, 

 although they agree closely with Agabus. The tarsal joints are also 

 proportioned as in this genus. The coxal processes are less divergent 

 than in the recent forms with which I have compared this species, 

 but they are evidently somewhat shifted, as will be seen from their 

 position in the figure. On account of the peculiar preservation of 

 the specimen in hand the outlines have a haziness of definition defy- 

 ing close delineation. The figures are therefore more diagrammatic 

 than usual, and the vestiture of the hind tarsus must be considered 

 as a conventional representation, not as a copy. In the original, 

 the hau' prints are too obscure for reproduction in the camera lucida. 



Genus ANISOTOMA Illiger. 



ANISOTOMA SIBYLLA, new species. 

 Plate 24, figs. 5-8. 



Preserved in part profile. Head rather large, slightly deflexed, 

 pronotum regularly but not strongly arched on the disk, elytral disk 

 more arched and not continuing the thoracic curve. No sculpture 

 can be distinguished upon the head and thorax, but the elytra are 

 marked with rather distant shallow striaB, showing traces of lightly 

 impressed moderately large punctures, these punctures separated by 

 considerably more than their own diameters. Legs rather long, 

 front tibia broadened at tip and spinose on the anterior margin, 

 middle tibiae wanting, hind tibias about straight, more slender than 

 the anterior, with apparently three rows of short spines on the face, 



