Together they form a prehensile device. The claw folds against the propodus and can be used to grasp the substratum, which is often the narrow stems of hydroids and bryozoans. Because of the lack of space in the tiny body, parts of some organ systems, such as the digestive and reproductive systems, are housed in the legs. Diverticuli from the gut extend into the femurs and tibia of the legs and the female femora are expanded to provide room for the developing ova. The gonopores are on the second coxa but they are small and inconspicuous.
Pycnogonids differ from all other arthropods in having multiple, segmental gonopores.
The posteriormost thoracic somite bears the abdomen. The abdomen is vestigial and unsegmented. The anus is at its tip. Anoplodactylus Figure 1. The right oviger is omitted.