OF WASHINGTON, VOLUME XVI, 1914 171 



downward. There are five ocelli in a whitish area as shown on 

 the figure (fig. 4). The labrum (Ir, fig. 5) is large and broad like 

 an eyeshade; it covers and protects the mouth-parts, but works 

 at the same time as a scraper; it is firmly connected with the 

 front, no clypeus intervening but a suture (c.s.) is easily observed. 

 The front (/) is nearly triangular, the interior angles (i) being very 

 obtuse; the exterior angles (e) are acute and the posterior angle 

 (p) is approximately 60; the frontal sutures (/..s.) are slightly 

 inwardly curved. The dorsal portion of the epicranium is flat 

 and large, the epicranial suture (es) short, and on the ventral side 

 the epicranial margin is strengthened by a hypostomal chitiniza- 

 tion (h, fig. 6). The anterior portion of this margin forms a deep 

 and broad curve, within which are placed the second and third 

 pair of trophi. The posterior portion is one-fourth as long as the 

 anterior and borders on a broad gula (gu, fig. 6). The antennal 

 ring (a, fig. 5) is large and somewhat triangular, and the connect- 



Fig. II. Pupa of Hydroscapha. 



ing membrane is also large. The antenna itself consists only of a 

 small basal piece (b, fig. 5) which carries two long, slender proc- 

 esses, one of which is possibly the second antennal joint, the other 

 a sensitive papilla. On the end of the supposedly second joint a 

 very diminutive third joint seems to be present. 



The mouth-parts are well adapted to chew off and force into the 

 pharynx the jelly-like algae on which the larva subsists. The man- 

 dibles (fig. 9) have a very large, broad and depressed molar part 

 (mo) and a slender, upright, terminal part (t) ; the tip of which is 

 produced into a little hand-like rake; a pectinate lacinia mobilis 

 (Im) is inserted between the molar and the terminal parts. The 

 form of the maxillse (fig. 6) is very characteristic; they have a 

 large cardo (ca) and a well developed stipes (st), and a flat chiti- 

 nized lacinia (la) with a series of large, flattened setae and a spine- 

 like galea (g) close to the lacinia. The maxillary palpus is three- 

 jointed, the basal joint with a little process on the outside. The 

 labium (fig. 6) has short, two-jointed labial palpi and a fleshy 

 ligula (li). Both mentum (m) and submentum (sm) are well de- 

 veloped, almost quadratic. The large connecting lobe (me) be- 



