Cirrhipedes And Annelids

Cirrhipedes

These are animals:

• without eyes
• breathing by gills
• having a mantle and articulated arms with a horny skin.

We know only 4 genera of cirrhipedes.

They must be considered as forming a special class because they cannot be included in any other class of invertebrate animals.

They are like the mollusks because of their mantle.

We have to place them immediately after the acephalid mollusks since, like them, they lack heads and eyes.

However, the cirrhipides cannot be included in the class of mollusks.

Their nervous system displays, like the animals of the three classes which follow, a longitudinal marrow with ganglia.

In addition, they have articulated arms with a horny skin and several pairs of transverse jaws. Thus, they are in a rank below that of the mollusks.

The movements of their fluids takes place through a real circulation, with the help of arteries and veins.

These animals are established on marine bodies and consequently do not move around. Thus, their main movements are limited to those of their arms.

They have a mantle like the mollusks, nature could not gain any help for movements of their arms from that and was forced to create on the skin of these arms points of attachment for the muscles which must move them.

Thus, this skin is tough and rather horny, like the skin of crustaceans and insects.

Annelids

These are animals:

• with elongated and ringed bodies
• without articulated limbs
• breathing by gills
• with a circulatory system and a longitudinal marrow with ganglia.

The class of annelids comes after the class of cirrhipedes because no annelid has a mantle.

We place them before the crustaceans because:

• they do not have articulated limbs
• they must not interrupt the series of those who have them
• their organic structure does not permit us to assign them a rank after the insects.

They are very little understood.

But the degradation in organic structure continues to maintain itself.

From this point of view, they are inferior:

• to the mollusks, having a longitudinal marrow with ganglia.
• to the cirrhipedes who have a mantle like the mollusks

Their lack of articulated limbs does not permit us to put them where they break up the series of those manifesting this organic structure.

The elongated shape of the annelids, which they owe to their ways of living, whether buried in the damp earth or silt, or in the waters, where they live, for the most part, in tubes of different materials, which they leave and return to as they wish, makes them so like worms that all the naturalists up to this point have confused them with worms.

Their interior organic structure displays a very small brain, a longitudinal marrow with ganglia, some arteries and veins in which circulates a blood usually coloured red. They breathe through gills, sometimes external ones which project and sometimes internal ones hidden or not apparent.