GASTEROPODES. dll 
but the volutes had so diminished, that the later spawn did not exceed 
a line in diameter, and it resembled an upright spiral spring of eight or 
ten volutes, the lower affixed, the higher floating like a white thread in 
the water. Spawn was also produced at the surface, while the parent 
swam supine. 
The young attain maturity in six days, when the spawn dissolves 
and disappears. 
We have already adverted to the reproduction of the branchize in 
other species. A similar prerogative is enjoyed by those creatures with 
which we are now occupied. They assume many strange attitudes, and 
exhibit much violent action, more indeed than any other I am acquaint- 
ed with. While reposing supine just under the surface of the water, the 
tentacula are recurved like ram’s horns, the cornicula naturally directed 
downwards, and the branchial papillz crossed on the back. If active, 
or during progression, any interruption or annoyance is suffered, the 
branchix bristle up in resentment or defiance. During contention for 
prey all are in action, when the vehemence with which both they and 
the tentacula seem to strike is surprising. The animals also bite each 
other. Thus they appear to be very irritable—contentious even in their 
amours. Under such agitation some of the branchiz being detached, 
prove to be long, round, pointed, fleshy organs, very tenacious of life, 
contracting, extending, and apparently searching around them. 
Whether it be in accordance with the necessities resulting from such 
a disposition, or that the species is merely more subject or more exposed 
to mutilation, the defective organs are speedily repaired. Soon after 
capture of the six preceding specimens, one of them had lost a tentaculum 
by the root, and another was deprived of the right or left corresponding 
organ, but reproduction operated vigorously. Half of the defective ten- 
taculum was regained in a fortnight. Another specimen, after partial muti- 
lation of a tentaculum, followed by partial regeneration, lost the whole 
by the root on the 25th of September, and, on the 28th, likewise a cor- 
niculum, Thus the animal was wholly mutilated of the right tentaculum 
and the right corniculum, two important organs, though by what means 
is unknown. ‘The mutual animosity displayed between itself and com- 
