duller. It is commonly of an ochreous shade, with reddish-brown spots on the upper surface of the carapace and limbs. Usually the spots are prominent and almost continuous, especially on the carapace; they are then of a deeper shade, varying from red and brown to dark purple, and such specimens have large reddish spots across the top of the hand and the movable finger, and sometimes also the movable finger. The outer surface of the hands is a deep yellowish cream, and the hairs on the legs are coloured a very pale raw umber.

The orbits and lateral teeth vary somewhat in shape. The back is more rounded in the female, the gastric region especially being raised. There is no doubt that Miers was correct in uniting Heller's H. barbimanus with this species. The males are much larger than the females, and have enlarged equal hands. Specimens from Zostera beds at Akaroa have filamentous algae (Enteromorpha?) on the legs; as in the masking crabs, it is the pilose regions which are affected by the algae. The line on the hand, referred to in the case of H. sexdentatus, is present, and more prominent; it is granulated, and sometimes accompanied by rows of punctulations along the fixed finger.

Differences from H. sexdentatus have already been noted; the species may also be distinguished from the superficially similar crabs Hemiplax hirtipes and Helice crassa (which are also mud-burrowers, and are correspondingly coloured), by the shape of the orbits, which are short and rounded, and not continued to the side of the carapace, as in the species named. The three lateral teeth at once distinguish it from Planes minutus and from Cyclograpsus lavauxi.

The dimensions of the largest male and of the largest female in our collections are as follows:—

The habits of this crab require more detailed study. In the Heathcote Estuary, for example, it burrows in the mud flats, and also along clay banks; at Kaikoura it is common under fragments of rock, where the substratum is too stiff for the crab to be able to burrow; at Sumner, large specimens occur with H. sexdentatus under rocks on a sandy beach; at Taylor's Mistake it occurs in rock pools on a reef where there is no sand or mud and no opportunity of burrowing; at Kairaki Beach, at the mouth of the Waimakariri River, it burrows in stiff sand well above high-water mark. In the latter case it is half a mile from the sea, and some hundreds of yards from the river; and the burrows do not extend down to the level of the water. It is interesting to note that such diverse habits should be exhibited by a single species.

The distribution of this species suggests a link with South America; but according to Ortmann it is also closely related to H. erythraeus (Kossmann) from the Red Sea.