ventral in position, but has moved forwards to take up a position at the extreme anterior portion of the body, with the result that the clypeus and labrum have been pushed up and lie dorsal to it. Similarly, the deutero- and triterocerebrum have moved forwards, the former upwards over the oesophagus and through 90°, taking the triterocerebrum with it; the proterocerebrum lies behind these and has rotated through 90°. The triterocerebrum now lies on either side of the oesophagus and not above it, hence the deuterocerebrum has come to overlie the former. The Proterocerebrum consists of a pair of lateral lobes united along their middle line, and forms the greatest and posterior region of the brain. Each lobe gives off a nerve on either side to the lateral ocellus of its side, and anteriorly between the junction of the proteroand deuterocerebrum the nerve to the median ocellus is given off. Attached to the proterocerebrum on either side is a large optic lobe, wider than it is long, directed laterally. It gives rise to the optic nerve. Posteriorly and ventrally the proterocerebrum gives off the hinder region of the sympathetic nervous system, but it is possible that this may retain an internal connection with the triterocerebrum. The Deuterocerebrum consists of two well-developed lobes, one on either side directed latero-anteriorly, and connected to one another by a piece of nervous tissue forming the dorsal lobe of the brain. Each lobe gives off a double antennary nerve to the antenna of its side, the more anterior nerve being the larger. The Triterocerebrum lies ventrally to the deuterocerebrum on either side of the oesophagus. Each trito-cerebral lobe is connected with its fellow by a post-oesophageal commissure, which descends from each lobe and encompasses the oesophagus. It also gives rise to the two large para-oesophageal commissures which run downwards and backwards to the suboesophageal ganglion, and to the labro-frontal nerves which form the root of the frontal ganglion. The Sympathetic Nervous System. The sympathetic nervous system (Pl. 36, Figs. 20 and 21, Pl. 40, Fig. 34) resembles that of the saltatorial Orthoptera, in that there is a paired stomatogastric nerve, each with its own stomachic ganglion. A small triangular frontal ganglion lies in front of the brain, giving off anteriorly a nerve to the clypeus. Laterally, two nerves run lateroanteriorly and arch backwards to find connection with the labrofrontal nerves of the triterocerebrum. Each of these nerves gives off another pair which run forwards to innervate the mouth parts. Posteriorly the frontal ganglion gives off the recurrent nerve, which runs backwards beneath the brain to join a mass of nervous tissue representing the fused oesophageal and hypocerebral ganglia. It is probable that the corpora allata are included in this fused mass, as they are not represented elsewhere. A pair of bodies, at first thought to be these were afterwards revealed to be stomachic ganglia. From the antero-lateral aspect this mass gives off two connectives to the brain; postero-laterally on either side there arises a stomatogastric nerve, which descends to a medio-lateral position on the oesophagus and runs backwards to the cervicum, where it gives off a small whitish