The Strdtigrdjthji of y^. IT. LoiiislaiKi. — Va ikjIki n. 211 
parish* as far south as Victoria, this formation is represented 
bylignitie sands and clays devoid of marine fossils, but ligni- 
tiferous strata occur throughout the whole area of the Lower 
Claiborne. In Bossier, Claiborne and Bienville parishes fos- 
sils are found as casts in sandstone, and as ferruginous re- 
placements. In Webster, Bienville and Jackson parishes the 
fossils are usually obtained in glauconitic sands, although oc- 
casionally present in yellowish clay. Further south in the 
extreme southern portion of Bienville parish and in Natchi- 
toches and Winn parishes, the fossiliferous beds are very cal- 
careous and are rich in fossils, which are usually poorly pre- 
served. Osfrea selhfformis is often extremely abundant. 
There are slight paleontologic differences to be found in the 
fauna contained in the calcareous clays or clayey limestones 
of northwestern Winn parish and of Natchitoches parish, as 
compared with the fauna found in the glauconitic sands to 
the northwest: but both fauna? are beyond doubt Lower Clai- 
borne, and they are very closely related. From the southeast 
dip of the Eocene of Louisiana, it appears very probable that 
the calcareous beds above alluded to represent a horizon a 
little higher than the glauconitic beds to the north. Within 
the calcareous area at St. Maurice, Robertsville and George- 
town, Lower Claiborne fossils were obtained from glauconitic 
sands or greenish clays. These beds, from the close resem- 
blance of their fossils to those found in the calcareous beds, 
in all probability represent local lithologic differences in the 
horizon to which the calcareous beds belong. 
The Lower Claiborne formation rests conformably upon 
the lignitic, and passes conformably into the Cocksfield Ferry 
beds above. 
Of Dr. Lerch's division tiie following belong to tlu- Lower 
Claiborne : 
.lackson (in i)ai't ). 
Arciulia ("lays. 
Upper Ijijiiiilic (in part). 
Marine Clai burnt', 
Lowor Liu:niUc (at least in part). 
The sections shown in figs. Lt -« '^ ^i '">? ^"^^l *'< i)l!ite IX, 
indicate the general characters of tlie stage. 
*This part of tli<' Luwer Claiborne is Hilgard"s Mansfield group, 
\V\^. 1 is probably IJ^iiitic. 
