M.A. de Quatrefages on the Classification of the Annelides. 115 
summary descriptions and imperfect figures. If I had attached 
as much importance as M. Claparéde to the armature of the 
anterior portion of the trunk (pharynz), I should have run the 
risk of not knowing where to place many species to which their 
external characters, as far as they are known to us, allow a place 
to be assigned. Still more should I have found myself in this 
position if, like my honourable critic, I had placed the existence 
or absence of alternant generations among the number of generic 
characters. 5 
9. Ihave yet another remark to make with regard to the 
observations of M. Claparéde upon the Sy/llidea. The Genevese 
savant thinks that I have given the name of gizzard to the ante- 
rior region of the trunk ; but in this he has mistaken me. With 
me, as with my predecessors and with M. Claparede himself, 
the gizzard is the median, inflated portion which is so charac- 
teristic in the Sy/lidea. The anterior portion I call the pharynx 
or the pharyngeal region. It is the armature of the gizzard, a 
region of the trunk which is here almost constantly unarmed, 
that it has seemed to me useful to introduce into the list of cha- 
racters. As to the denticles, styles, &c., which so frequently 
arm the pharynz, I have mentioned them in the description of 
the species, but could not ascribe to them the same value as 
M. Claparéde, for the reason just indicated. 
However, if I had been placed in the same position as M. 
Claparéde, I should perhaps the more casily have been led to 
ascribe a value to the pharyngeal armature, which will probably 
be conferred upon it hereafter, as this armature itself appears 
to me something very exceptional. Upon this point, again, I 
regret that I cannot agree with my learned confrére. Indeed, in 
his ‘Glanures,’ to justify the importance which he attaches to 
this character, M. Claparéde adds, “In this I only follow the 
rule generally applied in the other families of Annelides, in 
which the pharyngeal armature is regarded as of great value 
even as a generic character.” 
These expressions evidently suppose that the armature in | 
question is situated in the same region of the trunk in the Sy/- 
lidea and in the Neretdes or Eunice. Now it is impossible for 
me to accept this conclusion, so far as it relates to the styles and 
denticles which arm the anterior portion of the trunk of the 
Syllidea. It is evident that they cannot be the representatives 
of the jaws placed in the median region of the trunk in the Ne- 
reides and Eunice. 
The distinction which I here establish between the different 
regions of the trunk is by no means artificial. I may refer to 
the fact that it rests not only upon the general form of the 
organ, the distribution of the muscular masses, &c., but also 
5 
