QUATREFAGE’S HISTOIRE NATURELLE. AD 
of Schmarda and Kinberg, it appears that many genera are 
cosmopolitan. He dwells upon his notion that the Oligocheta 
represent what he calls the true Annelida—the Polycheta ; 
the former being fresh-water and terrestrial forms, the 
latter always marine. Holding this view, he is led to doubt 
the occurrence of Naids on the sea-shore, such as the Pachy- 
drilus and Clitellio arenarius described by Claparéde. He 
suggests that a spring running down to the sea might account 
for their appearance, but cannot believe that they are marine. 
We ourselves, last summer, met with Clitellio arenarius at 
low-water mark in the Isle of Man, and the circumstances 
attending its occurrence were precisely those suggested by 
M. de Quartrefages. A small fresh-water spring ran into 
the sea at the point where Clitellio occurred, and spread 
itself over the sands. 
In the fifth chapter, on the “ History and Zoological Rela- 
tions” of the group, the literature of the Annelida, and the 
various arrangements of the class which have from time to 
time been offered, are discussed from their earliest day. We 
cannot here pass in reyiew the systems of all those who have 
attempted to arrange Annelids into natural groups, but we 
may compare the divisions of Cuvier, Grube, and M. de 
Quatrefages. The latter states that he has chiefly occupied 
himself in limiting the families or small assemblages of 
genera, which he considers of fundamental importance, 
representing, as they do, the Linnean genera. While Grube, 
with Cuvier, embraces in his class Annelida the leeches and 
earth-worms, as well as the marine setigerous forms, M. de 
Quatrefages, it will be remembered, only allows the latter to 
come under this class, separating the other groups as distinct 
classes. Other writers, again, have gone so far in the other 
direction as to include nearly all worms—the Turbellaria, 
Gephyrea, &c.—under this class Annelida. Cuvier took for 
the basis of his subdivisions the absence or the presence of 
respiratory organs. Savigny neglected this character, and 
founded his classification, in the first place, on the absence 
or presence of sete, on the structure of these parts, on the 
presence or absence of a distinct head, antenne, pharynx, 
and jaws. Blainville took aboye all things the general form 
of the body, the similarity or dissimilarity of the rings, the 
sreater or less complication of their appendages. Audouin 
and Edwards applied themselves chiefly to the modifications 
of the soft appendages, and regarded considerations drawn 
from the respiratory organs as of secondary importance. 
Grube occupied himself chiefly with the nature and develop- 
ment of the hard parts which arm the feet. M. de Quatre- 
