Puparium of Ephydra, viewed ventrally, slightly from the right side; claw-bearing segments numbered. b, patch of black plates on segments 1. The spines covering the body are omitted from these figures.

Side view of the hinder part of the body, showing the clasping-organ formed by the 8th and 10th segments.

Ventral view, in outline, with part of the body-wall cut away to expose the pupa within, a, anterior triramous spiracle-bearing outgrowth; d, cavity within puparial skin; e, pupal envelope; f, imago within the pupal envelope, diagrammatically represented; g, paired group of claw-like spines on 8th segment; i, anus; m, mouth; p, pharyngeal skeleton (seen through the skin).

Anterior end of a larva, showing the armature of the mouth and of the anterior margins of segments 1 and 2. a, anterior spiracular outgrowth; b, triangular group of spinose plates; m, mouth; n, the base of antennae (? = true head);'s, trifid sensory hairs.

The mouth enlarged. showing the probably “true head” retracted within. n, one of the antennae; h, “true head.”

Pharyngeal skeleton of the larva. m, mouth; p, pharynx.

Anterior spiracular outgrowth, with its air-canals passing back to the trachea (t) At edge of figure is seen a few of the plates (marked b in fig. 4).