428 M. Leuckart on the genus Sacculina. 



(fig. 6), and, being repeatedly bent and coiled up, fill the entire 

 space of the cavity, without, however, being anywhere firmly 

 connected with its walls. When unfolded, it appeared as if 

 all these bands composed only a single body, repeatedly ramified, 

 like a Flustra. 



Even with the naked eye, these bands are seen to consist of 

 an aggregation of small globules; on examination with the 

 microscope, the globules proved to be ova, which were united 

 together by a common clear and structureless interstitial mass. 

 This interstitial mass formed, to a certain extent, a framework, 

 each of the spaces of which contained an egg, just as is the case 

 in the ovisacs of Cyclops. There could not be the least doubt 

 that the body in question constituted a band-like and much- 

 ramified egg-tube, which in this case, instead of hanging freely 

 down from the body as in other allied animals, was enclosed in 

 a peculiar brood-chamber. 



The ova were nearly all in the same grade of development. 

 They contained a Nauplius-like embryo with a single eye, like 

 Cyclops, and with three pairs of long natatory feet. They did 

 not seem to have attained their complete development, as indeed 

 appeared from the fact that not a single free embryo was to be 

 found in the brood-chamber. As the attempt to free the em- 

 bryos from their egg-shells by pressure under the glass cover 

 was also unsuccessful, I am unfortunately not in a position to 

 state anything more exactly with regard to their form and 

 structure. 



The viscera remaining in our Sacculina after the removal of 

 this egg-tube (which was previously seen both by Cavolini and 

 Rathke) consisted, besides the above-mentioned fatty body and 

 the membranes of the brood-chamber, of a large cordate body 

 of compact structure, which lay upon the ventral surface (that 

 furnished with the cloacal aperture), and terminated with its 

 posterior pointed end close in front of the cloacal aperture. It 

 seemed as if this body was to a certain extent lodged in the chi- 

 tinous walls of the brood-chamber. At any rate, it cohered with 

 this membrane, and, on the other hand, presented similar rela- 

 tions to the fatty body above mentioned. 



The organization of this body is very complicated, and was 

 but imperfectly unravelled. It consists of a framework of chi- 

 tinous lamellse, which pass through it in various directions, and 

 form a kind of lattice, such as is indeed figured by Rathke, but 

 represented as far too regular. In the interstices of this frame- 

 work there is a mass the analysis of which is difficult, in which, 

 however, two kinds of structures could be distinctly recognized. 

 One of these structures was the ovary ; the other, no doubt, the 

 cement-gland. 



