_Latera_, three pair; the middle pair apparently corresponds with the upper latera of the other species of the genus. The two other pair of latera, together with the rostrum and sub-carina, form a whorl. The sub-rostrum lies by itself, a little beneath this whorl. The latera are smaller than the rostrum or the sub-carina. They are placed far distant from each other; their inner surfaces are triangular; their umbones point upwards; the rostral pair is smaller than the other two pair, which are of equal size. The exact position of the rostral latus differed on the two sides of the specimen examined; apparently its normal position is at the baso-lateral angle of the scuta. _Peduncle_, wide at the summit, longer than the capitulum; calcified scales small, not arranged very regularly; flattened, spindle-shaped, rather far separated from each other; imbedded in membrane, so that even their summits are rarely uncovered. The surface of the membrane is thickly clothed with spines, which are strong, thick, yellow, pointed, and furnished with large tubuli running to the underlying corium. These spines are arranged in groups of from three or four, to five or six. Besides these larger spines, the whole surface is villose with very minute colourless spines, not above 1/20th of the length of the larger ones. The surface of attachment is broad. This species, not being symmetrically attached to a coralline, the peduncle does not curve, as in most of the other species, towards the rostrum. The capitulum is above half an inch in length. _Mouth._--The labrum is much produced downwards, but yet the mouth is not very far distant from the adductor muscle: the upper part is bullate, forming a small overhanging point, and in longitudinal diameter equals the rest of the mouth. _Palpi_ blunt. _Mandibles_ with four teeth, strong, short, thick, the second tooth much smaller than the others; inferior angle broad, pectinated. _Maxillæ_ with a long, rather sinuous edge, which, near the inferior angle, has a narrow projecting point, bearing rather finer spines; there is, also, apparently, a very minute tuft of small spines close under the two large upper spines: there are, altogether, about twenty pair of spines, without counting the smaller ones. _Outer Maxillæ_, with the inner edge slightly concave, continuously covered with bristles; exteriorly, with a prominence covered with longer bristles. Olfactory orifices prominent, protected by a slight punctured swelling between the bases of the first pair of cirri.