1873.] 8331 | [Morse- 
tion by Mr. Bland,the tufts of spines readily separated from the girdle; the 
whole tuft is closely united together, and seems to be almost entirely super- 
ficial. The following figures represent an outline of the 
species, with a tuft separated and enlarged as well as a Fig. 10. 
single tuft, as it appears upon the girdle, showing as 
well the minute spines which project from the exterior 
border of the girdle. The bases of the spines in the tuft 
are abruptly truncated. 
A section of the girdle of Amicula Emersoni shows 
the shorter granules, which are but slightly embedded, 
as well as the longer spines, which are more deeply 
seated, and one spine intermediate between the long and 
short ones, which is again only partially embedded. 
These all arise from the homogeneous cartilagineous 
portion of the girdle, and do not reach to the muscular 
layer beneath, from which they are entirely separate. 
They are therefore probably immovable, save what mo- 
bility attends the folding of the girdle. 
I h ‘sf h ara Amicula Emersonié 
n worms, there is found, as characteristic 7, eMfingnene 
af the higher as well as many of the lower layer. 0. mus- 
: : cular layer. 
groups, the production of sete, or bristles, 
which perform important service in locomotion. Claparede says, in 
regard to the setz of worms, that “some authors regard them as en- 
closed in a sac, which is only an invagination of the integument; 
others think they are formed in an internal follicle, and only seconda- 
rily arise to the surface. This second opinion only is correct. In 
certain cases (in Hesione and others, for example), the whole bundle 
issues in a compact form through a single pedal aperture, but in 
others, the seta has its own orifice; this is the case especially with 
the flabelliform bundles. The pore from which each seta issues is 
not previously formed, but is perforated by the seta itself”? Mr. 
Lancaster regards the sete in the earth worm as secretions of the 
so-called setigerous gland. 
The arrangement of these setee in worms is usually upon the sides, 
in two series, above and below.2. They are moved by muscles, and 
not only have the power of protrusion, but freely swing back and 
forth. 
A marked feature of the Brachiopods is the peculiar sete fringing 
1In Pectinaria, a transverse row of long ones project forward from thehead. In 
Sternaspis, nine bunches project from the borders of each scutum behind. 
2 See translation of introduction to Claparéde’s paper, Ann. Mag. Nat. Hist., 3d 
Series, Vol. xx., p. 344. 
