SUPPLEMENT. 
517 
Graptolithus spinulosus ( n. s.). 
Stipe simple, flat; sides subparallel, gradually expanding from the base, 
' which is furnished with several minute setiform radicles : serratures 
not distinct, the margin sinuous, the prominent parts extended into 
slender ascending spinuliform processes. These spinules are about one- 
sixteenth of an inch distant from each other. 
This species presents no distinct serratures on the margin, which is simply un¬ 
dulating with the extension of the processes described, which probably mark the 
place of the serrature. It has been seen only in small individuals or fragments; 
but its great comparative width, the rigid distant spi¬ 
nules and absence of defined serratures are distinguish¬ 
ing characters. 
The accompanying figure is of a fragment of this 
species, twice the natural size. 
Geological position and locality. In the shales of the 
Hudson-river group : Near Albany. 
The Genus Gladiolites or Retiolites of Barrande was proposed for 
certain graptolitic forms having the general features of the biserrate 
Graptolites, as G. pristis, G. mucronatus, and others; but the structure of 
the entire substance of the stipe differs in being apparently minutely 
celluliferous or reticulate. 
The following is the description given by the author : 
Genus Gladiolites = Retiolites (Barrande). 
“ Polypier small, flat, triangular, elongate, formed of two series of sym¬ 
metrical cellules arranged along the axis. These cellules extend from a 
single internal canal, which occupies the central part of the polypier: 
their orifices are disposed upon the sides of the triangle; they make an 
angle with the axis, and leave no spaces between them.” 
“ The only known species has its surface covered with a film, which appears to 
envelope it.” 
