268 
SIDNEY F. HARHER. 
examine the same species whose foot-gland has formed the 
subject of Schmidt’s description. 
The foot-gland appears to me to be composed of two distinct 
portions ; — (i) the “ gland,” and (ii) the “ duct ” of Schmidt. 
The “ gland” consists of a small number of granular nucleated 
cells arranged round a central lumen, as described by Kowal- 
ewsky. (See fig. 21, a section passing somewhat obliquely 
through the foot, so as to avoid the “ duct.”) This glandular 
mass opens at the angle of the foot by a pore which has no 
connection with the “duct” (fig. 2). The latter in the three 
species I have examined is in reality an open groove (fig. 20), 
extending along the whole of the “sole” of the foot, as may 
be clearly seen by means of sections or of glycerine prepara- 
tions. The rows of cells described by Schmidt along the 
“ duct ” are the high ectoderm cells lining the open groove. 
In certain conditions, when its edges are closely approximated, 
the appearance of a closed duct is produced. The foot-gland 
originates as a longitudinal groove on the anterior side of the 
base of the bud, which is attached to the adult by that portion 
which will ultimately become the free end of the foot. During 
the period when I had fresh Loxosoma at my disposal, I 
failed to give any special attention to the development of the 
“ gland,” but (from glycerine preparations) it appears to me 
that the longitudinal groove, soon after its formation, becomes 
constricted into two parts (fig. 19) — a longer dorsal and a 
shorter ventral portion. The latter forms the “ gland ” after 
becoming completely separated from the elongated portion of 
the groove, which persists as such in the adult. 
Nervous System. — The character of the nervous system of 
Loxosoma has always been exceedingly doubtful, although 
from the analogy of Pedicellina there could never be any 
real question of the existence of a ganglion between mouth 
and anus in the former. Such a structure has, however, never 
been correctly described, Salensky’s identification being, as I 
shall attempt to show, erroneous. As a matter of fact, the 
ganglion has been unmistakeablv figured by ^itsche (10), 
Schmidt (11), and Salenskv (15), but by all these observers has 
