I i:> l ACEA. 



July, th'-y produced ei^ht spots of spawn between the 6th and 15th of 

 August. If equally prulilio, four belonged to each. 



Those spots contained from live to eight embryos. Figs. 8 and 9 

 nre representc 1 to ho of the natural size ; fig. 10 natural si/xj ; fig. 11, the 

 same, more t-nlai _''! ; li^. 12, spot natural size; fig. 13, the same, en- 

 largo- 1. 



Tin- spot. ti^s. 10, 11, was produced on August G, and two of the 

 young quitted it on the iMth. Thus attaining maturity in eighteen 

 days. One of those, contained in the spot, figs. 12, 13, which had been 

 deposited on August 1 1, attained maturity on September 6, being twenty 

 three d;i\s. 



The figure of tlie nascent animal is less definite than that of adultv 

 Then- i- -till a greater difference in the shell. The shell of one while 

 included in th- spawn, seemed to be fluted. Nor was this an illusion ; 

 it proved, in fa<t, to le so. But the fluting is probably obliterated with 

 age. The shell of the nascent animal just specified of figs. 12, 13, 

 though not u quarter of a line in diameter, was sulcated from the apex 

 down to the maririn, fig. 14. The same was equally conspicuous on the 

 internal surface, which may be elucidated from the inside of another 

 cimen as enlarged, fig. 15, and more highly enlarged, fig. 1C. 



Perhaps the whole spot of spawn may be itself compared to a capsule 

 :itainin.u the individual ova, which seemed to be of a faint yellow 

 colour. 



The animal certainly renovates lost parts of the shell, where the 

 losses are not destructive of the tenant, as was proved under favourable 

 circumstances. A more distinct view of the contents will then gratify 

 the beholder. Thus, the upper surface of the anterior of an animal sur- 

 \i\iiiir privation of half the shell appeared reddish, and a distinct \ie\\ 

 was afforded of the position of the eyes. Fig. 17, enlarged. 



These creatures seem constantly employing the mouth to besmear 

 the neighbouring surface of the substances whereon they rest. They feed 

 readily in confinement ; propagate also ; and they survive during a 

 siderable perio 1. 



If contained in a small-necked or any other phial, and so are inac- 



