118 
AUG. F. FOERSTE 
Dictyophlois reticulata illinoisensis Var. nov. 
Plate XII, and plate XIII, fig. 12. 
Cf. Dictyophlois reticulata Foerste, Bull. Torrey Bot. Club, 
42, 1916, p. 675, pi. 33. 
Plate XII presents the appearance of the specimen in its present 
condition. Figure 12 on plate XIII presents the appearance 
of an impression of a part of the same specimen, in which the 
cavities of the first figure stand out as projections. 
Specimen 150 rrtm. in length and about 80 mm. in width; part 
of a rhizophore, whose original diameter can not be determined. 
In its present condition the specimen is flattened. The view 
presented on plate XII is assumed to be that of the exterior of 
the cortex. The round areas of attachment of the so-called 
rootlets vary from 3 to 4, occsionally 5 mm. in diameter. They 
tend to be arranged in diagonally insecting rows, so as to be 
from 8 to 13 mm. apart. At these attachment areas the surface 
of the rhizophore is abruptly depressed, and from the bottom 
of the pit there rises a short circular elevation with a small central 
pit. Some of these small central pits have a central tiny eleva- 
tion. The round areas of attachment are surrounded by a 
single series of radiating depressions, usually from 20 to 25 in 
number. These radiating depressions vary usually from 2 to 3 
mm. in length, but occasionally are shorter or longer. In the 
areas between the radiating groups of depressions the meshes of 
the remainder of the reticulated surface usually average about 2 
mm. in diameter, though a few may be as much as 3 mm. in 
diameter. 
Locality and formation.' — From the Carroll place, in Pope 
county, in the southern extremity of Illinois, in the Chester 
formation. 
Remarks. — Evidently the structure of this Illinois specimen 
is very similar to that of the Kentucky type. The question 
arises whether they are identical. Apparently the zone of radiat- 
ing depressions surrounding the attachment areas of the rootlets 
tends to be depressed below the general level of the surface in 
the Kentucky type, while in the Illinois specimen the descent 
