GASTEEOPODES. 311 



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 branchiae 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 papillae crossed on the back. If active, 

 or during progression, any interruption or annoyance is suffered, the 

 branchiae 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 branchiae 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- 



