fork being very short and diverging only slightly. This inverted Y-shaped suture must represent the epicranial suture of other orthopterous insects (e.g. Blatta), but in this case the anterior arms are very much reduced and evanescent (Fig. 25). The anterior arms are on a ridge and between them is a small elongate slightly-depressed area. The ocelli are frequently wanting in the Locustidae. They are represented in Hemideina by minute pale coloured circular areas. The lateral ocelli are situated one to the outside of each anterior arm of the epicranial suture. Below these, between the antennae and carried on a projection of the front, is the median ocellus. The compound eyes are pear-shaped. Each is surrounded by a chitinous ring, the ocular sclerite, which is more prominent on the median than on the lateral aspect. There is a small white area at the dorsal end of each eye. The antennae are situated to the inner side of and partly below the compound eyes. At the base of each antenna is a chitinous ring, the antennal sclerite, most prominent on the median aspect. The basal joint of each antenna articulates with a laterally-placed process on the antennal sclerite and is connected all round to the antennal selerite by a membraneous area. The basal joint is long and cylindrical, the second shorter, the third longer than the second but shorter than the first, and the remainder small. The antennae themselves are as long as and longer than the body. The front is limited distally by the invaginations forming the anterior arms of the tentorium, laterally by a ridge extending on each side from the base of the compound eye to the above-mentioned invagination and directed slightly outwards, while proximally a median projection of the front extending a short distance between the antennae bears the median ocellus. In the male, the lateral ridges (frontal ridges of Hutton) are rugose and blackened. In the male there is also, on the front, a pair of depressions, one to the inner side of each lateral ridge. The clypeus is separated from the front by the above-mentioned invaginations on each side, but for about the median third of its breadth is continuous with the front, the suture being obsolete. The clypeus is divided transversely into post-clypeus and ante-clypeus. On each side the post-clypeus is confluent with the trochantin of the mandible. At the junction on each side of trochantin and post-clypeus is a concave process for articulation with the ginglymus of the mandible. The ante-clypeus is white and membraneous and has two small chitinous plates in a transverse line. It can be withdrawn under the post-clypeus, thus raising the labrum which it carries. The gena forms the side-wall of the capsule. It is limited from the front by the lateral ridge of the front, and from the trochantin of the mandible by the invagination forming the anterior arm of the tentorium. No sutures separate it from the epicranial or occipital regions. The posterior surface of the capsule is the occipital region, adjoining and enclosing the occipital foramen. On each side the occiput carries an acetabulum in which the condyle of the mandible works. From this acetabulum, an invagination or apodeme extends dorsally along the occiput for a short distance. Surrounding the occipital foramen on each side is a rim, with whose ventral end the cardo of the first maxilla articulates. At about half its length