324 GASTEROPODES. 
These creatures seem to be opaque, solid, and heavy, and swimming 
with some exertion. The skin of the capsule was still too dark to admit 
exposure of any delicacy of organization, should it have been then unfold- 
ed. It only shewed the observer that they might be inscribed in rude 
spherical triangles, fig. 15. However, the capsular integument attenuat- 
ing its form for days, the tenants were distinguished by great activity, 
while their precise form could be ascertained. On the 18th, almost alk 
the capsules were quite freed from the sandy investment, now fallen in 
grains to the bottom, and then were beheld multitudes of beings swim- 
ming as so many specks at large in the water. 
The numbers, now liberated, uniformly resembled the Nautilines so 
often described, only the cylinders seemed wider, and the sac or contents 
of the shell shorter than in any of the others. Their course was swift 
through the element, and the action of the cilia rapid. In all respects, 
allowing for the flexibility of the parts, their whole organization and 
habits, as far as I could determime, were to be identified with those of 
the rest, fig. 14. Such was the appearance of this numerous brood of 
Nautilines, and thus it contimued until June 25, But they were very 
different when in retreat. In two days, only two of the multitude re- 
mained active. None survived in two days more. Their contents were 
speedily dissolved. Their shells, now empty, admitted of the most fa- 
vourable microscopical inspection. They are white, rather pearly, con- 
sisting of a single volute, with a circular orifice, so wide as to exhibit no 
contraction whatever, fig. 16. 
I was induced, by various reasons, to conclude these observations, cor- 
roborative of a course made eight years previously, though shorter, and 
with less perfect instruments. At that time the capsules of a cluster 
were rated at sixty or seventy, and the Nautilines included apparently 
larger than the last when free, were computed ut thirty or forty in each. 
There were five capsules from the unknown parent, connected by slender 
ligaments, fig. 17 ; enlarged, fig. 18, three Nautilines from them; fig. 19, 
their empty shells. 
The included animals traversed the whole fluid contents, which, 
