NATURAL HISTORY MISCELLANY. à 55 
All of the specimens are quite small, the largest hardly exceed- 
ing three inches in height. In my Windsor plant the presence of 
stomata is at once apparent; the spinules on the macrospores are 
short, thick, and in connected ridges ; the microspores being abun- 
dant and characteristic of the species. In the Sandwich plant the 
stomata, though present, are more difficult to find, being very few 
and indistinct; and the macrospores, though of equal size with 
those of the former plant (about 0.23 in diameter) differ in being 
provided with spinules which are long, slender, and, occasionally, 
slightly forked. No microspores were observed. The presence of 
stomata in both these distinct forms of this species, which is a 
most variable one, is worthy of note. — Henry GILLMAN, Detroit, 
Michigan. , 
ZOOLOGY. 
A New Genus or Bracnrorops.— Among some small shells 
(supposed to be the young of Waldheimia cranium), recently re- 
ceived from the Northeast Atlantic, through Mr. Jeffreys, were 
three specimens of an undescribed genus of the subfamily Terebra- 
tuline. The shell resembles Magasella, being smooth and with an 
incomplete foramen. The loop nearly resembles that of Ismenia 
sanguinea Chemn., but has no secondary attachment to the hemal 
valve, and the latter is destitute of a septum. I propose, for the 
genus, the name of Frenula, from the bridle-shaped loop ; and, for 
the species, that of Frenula Jeffreysii. More extended descrip- 
tions are in preparation. — W. H. DALL 
EMBRYOLOGY or LmmvuLus. — A reviewer in the Quarterly Jour- 
nal of Microscopical Science (Jan. 1871, p. 89), seems to think it 
very little to our credit that the embryology of Limulus should have 
remained so long unknown, “seeing that they are favored by its 
_presence in abundance on their coasts.” This is hardly a charitable 
view to take of the subject, and shows that the writer of the notice 
has not the most remote idea of the difficulty attending researches 
on the sea coast. It is impossible to make connected observations, 
without extending them over a long series of years, and no one who 
is not thoroughly familiar with the habits of any marine animal at 
all seasons of the year, can hope to accomplish anything more than 
the most fragmentary work. The time of spawning of many of 
our most common inhabitants of the coast, is often very short, 
