396 
BULLETIN OF THE NATURAL HISTORY SOCIETY. 
shale. A Nairopteris occurs which is net N. polymorpha, Dn., so 
abundant in the higher measures. An obscure Spbenopteris and 
tw'o forms of Pinnularia (one is P. dispalans, Dn.) occur. 
In consequence of the coarseness of the matrix it is difficult 
to read the intimate characters of these ferns, but it is evident that 
the flora occurring with Pseudobaiera was somewhat varied. 
Mutation flabellata, n. mut PI. VIII. fig. 7. 
In this form the pinnules were somewhat more than half an 
inch apart on the side of the rachis. The pinnules appear to have 
been about one and a half inches long and were about three- 
quarters of an inch wide ; they were thinner than in the 
typical form and the lobes more spreading; also the ends of the 
lobes were more frequently and more deeply gashed; the veins 
also are more readily seen. 
Horizon and Locality . — Found in Plant Bed No. 2 of Hartt's 
series. — Scarce. 
I have had this form in my collection for many years, but 
thought it too imperfect for description. It is now clearly seen 
to be related to the plant discovered by Mr. McIntosh. 
ANNULARIA Brongn. 
Not far above the bed containing Pseudobaiera Mr. Leavitt 
discovered a fine example of a plant of this genus. It may 
referred to Brongniart’s. 
Annularia longifolia. 
As a variety or mutation under the name of 
mutation Leavitti, n. mut, PI. IX. 
Stem about 3 mm. wide. Length between the internodes 30-37 
mm.; about 24 leaves in a whorl; length of leaves 30-50 mm.; 
width 3-6 mm. ; there is a strong mid-rib and a slender pointed 
tip. 
