16 
guished and the way in which the product of this gland must be 
conveyed to the exterior is necessarily between the interstices of 
the eiliated epithelium uf the ventral groove. The cells are gener- 
ally elliptical and tend with their long axis towards this groove; 
some of them are visibly provided with a somewhat elongated pe- 
diele, i.e. more or less flaskshaped. The contents are finely gran- 
ular and hardly stain at all with pierocarmine. The nucleus on 
the contrary stains well, a distinet nucleolus is also present. The 
average size of the cells is 0.025 mm., of the nucleus 0.007 mm. 
(ig. 25 & 26). This complex of cells is traversed in all direetions by 
muscular fibres and by bloodlacunae; there is a certain resemblance 
between its general aspeet and that figured by SOCHACZEWER (29) 
for the footgland of Lima. 
As the anterior portion of the footgland has to be regarded as 
a distinet subdivision, so the pcrtion situated at the opposite ex- 
tremity might give rise to still more serious doubts about its 
identity with the rest. 'The portion here alluded to, lies below 
the ducts RR and in longitudinsl sections it is not even directly 
continuous with our „posterior foutgland’ along its whole breadth. 
This part is again traversed by deep and ramifying ceiliated cavi- 
ties in direct continuity with the hinder portion of the ventral groove 
(ig. 32). Moreover it would appear from certain sections that 
these cavities communicate in the opposite direction with the body 
eavity, 1. e. with the lacunue in the mesenchym. As a curious 
yellow massive secretion, strongly mixed up with black pigment 
is contained in the greater part of the ciliated cavities just men- 
tioned (fig. 60), I was at first inclined (Zool. Anzeiger n’ 70) to regard 
this as a kind of renal organ (nephridium). The innervation from 
the pedal commissure as well as other eircumstances have how- 
ever rendered this interpretation exceedingly improbable, and I 
shall hereafter have occasion to discuss this question more thoroughly. 
For the present I must content myself with the few remarks here 
‘ given, moreover notieing that the cells composing- this gland, 
though of the same shape as those of the posterior footgland, show a 
somewhat different reaction towards pierocarmine, are of smaller 
