6 Mr. Woops on the Genera of European Grasses. 
which I adopt. He does not seem to have found it necessary to assign a 
name for the two together. I shall with Linnæus term it a corolla, but 
composed of two palec instead of petals. This nomenclature seems more 
unobjectionable than that of calyx to the outer covering; and if Mr. Brown 
has not absolutely proved, he has at least shown it to be highly probable that 
these parts are analogous to the outer series of a hexapetalous corolla. 
Awn. Attached to the outer palea we frequently find an awn, whose presence 
nature and position are often very useful in determining species, and sometimes 
in characterizing genera. Palisot de Beauvois maintains that two organs es- 
sentially distinct have been confounded under this name. To one of them he 
applies the name of sera, and describes it as the prolongation of a nerve, 
whose base forms part of the substance of the paleæ. It is not necessary that 
it should accompany the palez for the whole length of the latter, but may 
divide from it in any part. The awn originates suddenly from the substance 
of the palea, and if there should be a nerve below, it is much smaller than the 
awn, and is considered to be prolonged into a seta embraced by the awn 
and adhering closely to it. When broken off, the awn leaves behind no trace 
of its existence. Neither Duby nor Kunth seems to acknowledge this distinc- 
tion. Gaudin adopts it with some modifications. P. de Beauvois has added 
to the above characters that the awn is stronger than the seta, and of a firmer 
texture. Gaudin, on the contrary, shows that the awn is frequently as fine, 
tender and delicate as any seta, as in Aira and Agrostis, which are acknow- 
ledged to be awned by P. de Beauvois himself; and, on the other hand, in 
Triticum, where both authors are agreed that the terminating point is a seta, 
it is firm and thick, so that few awns can exceed it. He takes, therefore, 
principally for his guide its fragility at the point of insertion. P. de Beauvois 
assigns a seta to Festuca and Brachypodium, and an awn to Bromus. Gaudin 
considers all these genera as setigerous. The nature of the arm may doubt- 
less afford sometimes a very useful distinction, but I am afraid it will be 
impossible to regard it as including two things which can always be clearly 
distinguished. The seta is a mere continuation of the midrib. The awn is 
something different or something more; the peculiarity pointed out by Gau- 
din will usually explain its nature. 
Scares; SqUAMULA. Within the outer paleze, but without the stamens, are 
