220 
Atkinson. — A Monograph of the 
maturity and brittle when dry. Antherid-zone not prominent ; 
antherid-band broad as shown by the marks of the basal 
tissue remaining after fertilization ; procarps in the middle of 
the procarp-zone ; spores often aborted and undeveloped : 
mature ones large, ovoid or spherical; 31 ja-45 jit . 
Note. I have carefully examined specimens of this species 
from Wolle’s herbarium and from Rabenhorst’s Alg. Europ. 
No. 2538, and find it to be a Lemanea. Through the kind- 
ness of Dr. W. G. Farlow I have had the opportunity of 
examining specimens of Tuomeya Jluviatilis Harv. from 
Harvey’s herbarium. It is very different from Wolle’s 
Tuomeya grande ( Entothrix grande Wolle). I have made 
careful dissections and find Wolle’s Entothrix is identical 
with the characters of the subgenus Lemanea. Fig. 46 repre- 
sents a section showing the enveloping filaments dissected 
away from the central axis at the point where the cruciate 
branching of the ray-cells occurs. The dissection was also 
made to show the origin of the spores: a represents the 
procarp, the chains of spores radiate from the region of the 
carpogenic cell. It is so firm at maturity that it is necessary 
to use patience and care in removing the filaments which 
surround the central axis. With little difficulty however the 
procarps are found. The interlacing of filaments on the 
interior of the tube is common in some other species of 
Lemanea. The cortex develops two to three cell-layers, 
as in L. nodosa Kiitz. and L. australis Atk. Sometimes by 
hypertrophy of the tissues of the antherid-zone several more 
layers are developed. 
Habitat. £ In shallow, sluggish river water,’ Bethlehem, Pa. 
Some younger specimens of a Lemanea collected at Falkland, 
Del., by Mr. Commons (Herb. W. G. Farlow), I have re- 
ferred to this species. Mr. C. H. Green, Chester, S. C., 
collected specimens of a Lemanea in the Catawba river, which 
1 During the winter of 1887-88 the author received specimens of this species 
from the herbarium of Rev. Francis Wolle, and discovered it to be a Lemanea , 
but did not publish it at the time as it was considered to be more valuable to hold 
it until the completion of the present Monograph. 
