348 Prof. E. Claparéde on the Structure of the Annelida. 
More or less complete muscular floors sometimes divide the 
perivisceral cavity into several chambers. M. de Quatrefages 
cites, as presenting this arrangement, the genus Polyophthalma 
and Terebella conchilega. Many other examples might be cited. 
Such are:—the Opheliea, the Polycirrida, many Terebellea, the 
Aphroditea, and the great majority of the Annelida Errantia, in 
which the perivisceral cavity is divided into three longitudinal 
chambers; the Glycerea, in which it is divided into two, &e. 
Digestive Organs. 
For the different parts of the alimentary tube and, especially, 
of the trunk, M. de Quatrefages has endeavoured to establish a 
complete nomenclature, the opportuneness of which is at least 
contestable so long as the homologies upon which it is supposed 
to be founded are by no means demonstrated. Why, for exam- 
ple, in the Syllidea, should we give the name of dentary reyion 
of the trunk to an organ with glandulous walls, which constitutes 
no part of the trunk and contains no teeth*? The names em- 
ployed by other authors—such as fleshy portion of the pharynx 
(Milne-Edw.), gizzard (Williams), and proventriculus (Girsted)— 
appear to me to be very preferable. Are there any sufficient 
reasons for setting aside the names ventriculus and glands of the 
ventriculus, employed originally by Rathke for the Nereidea, and 
repeated by his successors? Is it really necessary to replace 
them by those of wsophagus and salivary glandst+? I do not 
think so. Rathke’s names were at least justified by analogy. 
One generally regards the salivary glands as more or less con- 
nected with the buccal cavity, whilst the glands in question 
often occur twenty or thirty segments behind the buceal seg- 
ment. 
In certain Annelida the posterior region of the intestine, fol- 
lowing the biliary region, acquires a peculiar appearance. Its 
wall becomes filled with cells secreting curious concretions de- 
stined, no doubt, to be eliminated with the feces. I designate 
this part of the intestine by the name of the urinary region, 
although, chemically, it does not seem to contain any uric acid. 
* M. de Quatrefages, it is true, enumerates a certain number of Syllidea 
armed with teeth in this region; but we shall find that in most cases, pro- 
bably even in all, there is an error, and that the worms in question belong 
to totally different families. 
+ This name of salivary glands is indeed borrowed from Rud. Wagner, 
who employed it, as well as that of poison-glands, because he assumed that 
a canal starting from these glands penetrated to the extremity of the jaws. 
This canal does not exist. (See “Zur Anatomie von Nereis,” Isis, 1834, 
». 133.) 
{ I shall speak of this again in more detail in connexion with certain 
Syllidea. 
