The ersaeome (Calycophorida), made up of the same appendages as the preceding type but with the addition of a nectocalyx; when free termed Ersaea.
The appendages of the body are reduced to branchiae, present in certain forms. A clitellum is present.
Lacuna, foot with two posterior appendages, marine, entirely aquatic. Cremnoconchus, entirely aerial, Indian.
It has been shown by C. Janet (1889), from careful studies of the musculature, that the greater part of the head-capsule is built up of the four anterior head-segments, the hindmost of which has the mandibles for its appendages, and this conclusion is in the main supported by the recent work on the head skeleton of J.
In common with the okapi, giraffes have skin-covered horns on the head, but in these animals, which form the genus Giraffa, these appendages are present in both sexes; and there is often an unpaired one in advance of the pair on the forehead.