laterally directed, fleshy tubercle at each caudo-lateral margin. (Those of segment 8 shown in fig. 6). Segments 5 and 6 have very minute tubercles in the same positions.

Spiracular disk dorso-caudal. When expanded (fig. 7) occupy dorsal half of caudal aspect; when contracted (fig. 6) visible only as a transverse dorsal slit at about two-thirds the length of 9th abdominal segment. Of the six lobes borne by disk, the ventral pair are very large and fleshy, almost fused in median line; their apical margins with brown, chitinized lines. When disk is expanded the faces of ventral lobes are at right angles to vertical face of disk proper and form a horizontal shelf whose area is equal to that of disk. In contracted condition the faces of ventral lobes are turned upward to a nearly vertical position, concealing spiracles and face of disk, and in this position the fleshy caudo-ventral faces of ventral lobes form a tumid caudal end to the larva. From the middle of the caudo-ventral face of each lobe is borne a small, cylindrical, fleshy papillus. The disk proper is sub-quadrangular, the long dimension of quadrangle, dex-tro-sinistral. The nearly circular spiracles are dark brown, their centres a dead black; they are separated by about once and a half times diameter of one spiracle. The slender, conical, dorso-lateral lobes project dorsad from dorso-lateral angles of disk and at about mid-length turn abruptly laterad; the caudal face of their bases has a chitinized, faint brown line. The paired dorso-median lobes are very small, rounded, chitinized projections to either side of dorso-median line. From cephalic surface of each arises a small, fleshy, conical papillus that projects dorsad well beyond lobe itself. Save for the spiracles and chitinized areas noted, disk is concolourous with rest of abdomen.

The anal gills have the form of a broad circum-anal ring that is radially wrinkled, and are opaque white save for a dark brown, chitinized outer portion. When gills are retracted only this chitinized outer portion is visible. Apparently the gills serve as an organ of locomotion.

Head capsule (fig. 1), broad, massive, compact, heavily chitinized. Length, 3.5 mm.; breadth, 2 mm.; greatest depth (mid-length of lateral plates), 1.3 mm. Prefrons a long narrow triangle, its slightly concave base forming anterior margin, posterior apex slender, elongate; anterior two-thirds heavily chitinized, dark brown. Lateral plates mussel-valve-like in shape; anterior three-quarters and entire margin heavily chitinized, dark brown; the centre of posterior quarters membranous, yellowish brown, ventro-mesal anterior margins projecting to form the bars of mentum, toward lateral angles of dorsal cephalic margins with a single stout, long seta. Clypeus shallow crescentic, chitinized, dark brown; cephalo-lateral horns with a single, erect, brownish yellow seta. Labrum epi-pharynx rectangular, almost square; a transverse groove caudad of its cephalic margin; back of this groove the surface is slightly depressed, saucer-like, conspicuous whitish yellow; anterior to groove with cephalo-lateral margins chitinized, dark brown, bearing numerous long, stiff hairs and a pale slender papillus-like rod, the median cephalic portion emarginate. Antennae with first joint stout, cylindrical, dark brown except for yellow apex; 2nd joint minute, elongate oval, yellowish white. Man-