Culex pervigilans, and very little variation in depth of colour has been observed. Length of larva in fourth instar—6 to 7 mm., without siphon.

Head (Fig. 14) dark, almost black, chitinised, slightly narrower than thorax, front rounded, slightly expanded laterally at the level of the antennae, posterior margin rounded. Pre-clypeal hairs short, stout at base, tapering, bent sharply inwards almost at right angles and sharply-pointed. Pre-antennals fairly long and pointed. Outer anterior clypeal hairs consist of three sets of trifid and quadrifid branches of simple hairs, which reach almost to the proximal third of the antennae. One trifid tuft of simple hairs is situated posteriorly and centrally to the antennae. One anterior ocular and one posterior ocular quadruple tuft. Eye moon-shaped, fairly large, Maculation absent.

Antennae almost cylindrical, infuscated, antennal plume a single hair situated approximately at the apical two-thirds, in length reaching half the balance of the distance to the terminal. The terminal hairs are composed of one long and two shorter ones; a short spine-like process arising from a papilla is also present.

Mentum (Fig. 15) index 2.2: 1.10, triangular in shape, one central tooth at the apex, much larger than the side teeth. Eleven smaller incurved teeth each side, these teeth decrease in size posteriorly, the last one being very much smaller than the others.

Fig. 15.—Mentum of larva of A. notoscriptus.
Fig. 16.—Maxillae of larva.
Fig. 17.—Mandible of larva.

Base much crenulated symmetrically. Maxilla (Fig. 16) ovate with rounded apex, one strong spine on the outer margin, numerous diverging hairs arise from near the apex; one strong process on the inner margin. Mandible (Fig. 17) quadrangular. On the outer margin is a pair of strong, elongated recurved spines, pointing upwards; immediately below is a rounded stumpy spine or process. The premandible has one large tooth and three smaller below; along its upper surface and below the margin is a line of strong recurved hairs, which continue across to the opposite margin. Five short strong spines on posterior margin.

Thorax from above (Fig. 18) not much wider than head, angulated, mesothoracic and metathoracic chaetotaxy composed of groups

Fig. 18.—Thorax. Dorsal view of larva.
Fig. 19.—Ventral view of thorax of larva.

of long spinose hairs which are found arising from slightly chitinised papillae; several short sharp spines stand in close proximity to the hairs also. For ventral chaetotaxy see Fig. 19.

Abdominal segments on the dorso-lateral margin of each is one long bifid hair, minutely pubescent on the proximal third; these

Fig. 20.—Terminal segments of A. notoscriptus larva.
Fig. 21.—Comb scale from 8th segment.
Fig. 22.—Pecten spine of siphon.

hairs decrease in length on each successive segment posteriorly, several short trifid, bifid, and single hairs are to be seen on the angulations of each segment. Terminal segments (Fig. 20): lateral comb on the eighth comprises 30 to 36 scales in a triangular mass, not in regular lines; each scale (Fig. 21) has a fringe of fine hairs on the widest part of the free margins. Several single, bifid, trifid and quadrifid hairs are seen on this segment, all simple. Siphonal plume a quadruple tuft almost as long as anal segment, simple. Sub-siphonal plume same as last. Anal plume a single hair also simple.

Siphon infuscated, barrel-shaped, chitinised, twice as long as broad, siphon index 1.6: 0.9, slightly tapered after the apical two-thirds; the siphonal valve large and prominent, several hairs on the outer and inner margins. Pecten consists of 13 to 18 strong spines, which run up more than half the length of the siphon, increasing in size distally, terminated by one tuft of three simple hairs. Each spine (Fig. 22) has a circular base and the apex sharply pointed, and bears three small and one larger spinelet. Arcus present, but small.

Anal segment not completely invested with anal saddle, strongly chitinised; on the distal portion of the saddle are several fine small spines. Sub-dorsal hairs as follows: two long strong hairs one on each side arising from a strong papilla, five other shorter strong hairs also arising from papillae, but only two-thirds the length of the former on the dorsal margin are several black strong short spines. Lateral hair (Barraud) is a bifid tuft and as Cooling remarks is sometimes quadruple, but seldom seen. The ventral beard consists of 10 to 12 groups of simple hairs, similar in length to the shorter dorsal hairs. Anal gills: the two dorsal gills are half the length of the sub-dorsal hairs, the ventral are shorter by a third, but in some instances I have seen them equal in length; they have been noted by other observers to be liable to variation; they are blunt at the apex, and rather wide up to the distal two-thirds, then sharply tapering.

The larva of Aedes notoscriptus hangs from the surface of the water at an angle of 75°, and its movement is of a serpentine nature by which it can easily be distinguished from the other species described herein. It bears a very close resemblance to that of Aedes (Ochlerotatus) antipodeus, but the former has a more barrel-shaped siphon, while the latter has a more rounded head with the antennae more curved, and a more horizontal, but still sinuous movement in the water.

A. notoscriptus and C. pervigilans are occasionally found breeding together, but the locality in these instances is always of the type characteristic of the former. It shows a decided preference for the darkest parts of water containers. I have frequently looked for it in troughs and have found plenty of C. pervigilans but very few A. notoscriptus. One day, however, on examining the covered-in part of a trough, where the ball-cock is protected by a covering, I found them concentrated there in large numbers. In an old barrel