A similar pair of coxal glands, lobate instead of ovoid in shape, was described by Lankester in Mygale, and it was also shown by him that the structures in Limulus called " brick-red glands " by Packard have the same structure and position as the coxal glands of Scorpio and Mygale.
Their movement in an upward or downward direction in Limulus and Mygale must exert a pumping action on the blood contained in the dorsal arteries and the ventral veins respectively.
An internal skeletal plate, the so-called " entosternite " of fibrocartilaginous tissue, to which many muscles are attached, is placed between the nerve-cords and the alimentary tract in the prosoma of the larger forms (Limulus, Scorpio, Mygale).
The largest of these is the Mygale with a body 2 in.
A large Mygale found on the island of Siriba, of the Abrolhos group, feeds upon lizards, and has been known to attack and kill young chickens.