MOLLUSCA. 4] 
separate. It includes the whole of the marine species of the 
Linnean genera of turbinated univalves. Into this order, 
Cuvier, from the consideration of other characters, has in- 
serted the genus Cyclostoma, which, according to the cha- 
racters indicated by the respiratory organs, belongs to the 
Pulmones. 
In the seventh order, termed Scutibranches, the bran- 
chiz are similar to those of the preceding order, but the 
sexes are united, each individual being capable of impreg- 
nating or being impregnated. The shells in general are 
cup-shaped, and destitute of a lid. It includes the genus 
Halyotis, and many species of the old genus Patella. In 
the last order, called Cyclebranches, the branchiz appear in 
the form of small leaves or pyramids strung round the under 
margin of the cloak. They enjoy a hermaphroditism simi- 
lar to those of the preceding order. The species of the 
genus Patella which are allied to the vulgata, and the genus 
Chiton, are included in this order. 
In the fourth class, or ACEPHALA, he includes the bivalve 
shells, distributing them into families, from characters near- 
ly similar to those which we have pointed out as having 
been previously employed by Poli. 
The fifth class, termed BRAcCHIOPODA, contains animals, 
resembling those of the preceding class in having a cloak of 
two lobes, but these are always open. The branchiz con- 
sist of small leaves placed on the inner margin of’ each lobe. 
In place of a foot they have two retractile fleshy arms, 
which are extensile. This class includes the Patella unguis 
of Linnzus, the genus Terebratula and the Patella anomala 
of Miiller. 
The class Crrrurpona, distinguished by the articulated 
filaments with which the animals are furnished, contains the 
