(A) Abrachius

The upper extremities absent, while the lower are developed.

Fig. 13. - Peromelus. The four extremities defective. (Glasgow Hunteriiin preparation).

(B) Perobrachius

Both arms are defective. The long bones may fail and the hands be planted on the shoulders, or the arms may be short and deformed, and the hands have only two or three fingers. In most cases, however, the upper arm is little deformed, but the fore-arm and hand are defective.

(C) Monobrachius

Absence of one limb. This sometimes occurs as part of a greater defect of the thorax and abdomen, but the body may be fully developed.