-o 
BERRY: SPECIES REFERRED TO THINNFELDIA 443 
THINNFELDIA Ettings. Abhandl. k. k. Geol. Reich- 
sanstalt, 1°: No. 3, 2. 1852 (restricted) 
Fontaine * gives the following diagnosis, which is very nearly 
that of Schimper: ‘Fronds bipinnate or tripinnate; pinnules 
varying much in size and shape, mostly oblong, ovate-lanceolate 
or oblong-lanceolate, decurrent and mostly confluent at the base ; 
coriaceous ; primary nerve of the pinnules dissolved before attain- 
ing the apex into many dichotomous nerves; secondary nerves 
going off at a very acute angle, diverging in ascending, several 
times dichotomous.” Filical remains from the older Mesozoic. 
Thinnfeldia Fontainei nom. nov. 
Thinnfeldia variabilis Font. Potomac Flora, 110. p/. 77. f. 3-7 
pl. 18. f. 1-6. 1889; Font. in Stanton, Bull. U. S. Geol. Surv. 
Bat 28S, - F808. 
_ Fontaine’s name is antedated by Zhinnfeldia variabilis Velen. 
(Gymnosp. Bohm. Kreidef. 6. p/. 2. f. 1-5; pl. 3. f. 72. 1885), 
an altogether different species as pointed out by Hollick.j It is 
fitting that the new name should commemorate the original describer. 
This is the most common fern near Brooke, Virginia, and re- 
appears in the Knoxville beds of Tehama County, California, the 
only species of 7hinnfeldia at all common in the Potomac or reap- 
pearing at any other locality. It is unnecessary to redescribe this 
species ; no one has ever doubted that it is a fern. Though spe- 
cifically different it closely resembles 7hinnfeldia rhomboidalis Ett. 
THINNFELDIA GRANULATA Font. Potomac Flora, 111. p/. 26. 
fi to-125 pl. 27. f. I-§, 8; ph 109. f. 1. 1889 
A rare fern found only near Dutch Gap Canal and near Potomac 
Run, Virginia, in the Potomac formation. Resembles Mariopierts 
muricata (Schloth.) Zeiller. 
THINNFELDIA ROTUNDILOBA Font. Potomac Flora, I11. 
PE 27. F206, 7. 1889 
This fern is still rarer than the preceding ; it is recorded from 
Fredericksburg and near Potomac Run, Virginia, in Potomac 
strata. Resembles Sphenopteridium dissectum (Gopp.) Schimper. 
* Potomac Flora, 110. 1889. : 
7 Bull. N. Y. Bot. Gard. 2: 404. 1902. 
