june,i 9 o 5 ] Knab: Inhabitant of Sarracenia Purpurea. 73 



On each side of the mouth a large, broadly rounded, flat lobe projects forward, cov- 

 ering the base of the mandible. Scattered over its surface are a number of setigerous 

 papillae and along the inner margin several spines. At the apex are the minute rudi- 

 mentary maxilla.-. The labial (fig. 4) plate is very large with a median slightly 

 toothed portion flanked on each side by five larger teeth. Overlapped by the labial 

 plate, and of similar outline with it, is the hypopharynx which bears an elaborate 

 arrangement of spines and setae. 



Body of 13 segments, of nearly equal diameter throughout. Prothoracic segment 

 somewhat longer than the succeeding ones ; anteriorly, upon its ventral surface is a 

 large retractile proleg. This is very broad, about three fourths the width of the 

 segment, and about half its length when extended. It is cleft for a short distance and 

 the two lobes are crowned with a dense brush of coarse simple hairs. Behind these 

 brushes are fine transverse ridges beset with minute spines, and these ridges are placed 

 in a series of about twenty closely set rows. The meso- and metathoracic segments 

 are short and almost fused together. There are no appendages of any kind until the 

 ninth and tenth abdominal segments are reached (fig. 5). The ninth abdominal 

 segment bears dorsally and ventrally a pair of tubular appendages, broadened at the 

 base and bearing at the apex a group of six stout and long black setae. The anal 

 segment is short and less in diameter than the preceding ones. At its tip, dorsally, 

 are four small leaf like blood gills and below these a pair of fleshy extensible prolegs. 

 The prolegs bear a circlet of large hooks of varying shapes and nearly all of them 

 dentate (figs. 6-1 1). 



Pupa (figs. 12, 13). Form rather elongate. Length 3.5 to 4 mm. Color cream 

 yellow, the disc of the thorax pale brownish yellow. Eyes ferruginous, the very 

 small accessory eye black. Eyes prominent and near the apex of the pupa, the 

 minute accessory eye below the compound eye and in contact with it. The antennae 

 pass behind the eyes in a prominent ridge. The wing pads extend nearly to the 

 lower margin of the second abdominal segment. Segments 2-8 with a dorsal trans- 

 verse ridge above the hind margin crowned by a crowded row of minute, rounded 

 spines pointing backward ; a ferruginous line along their base. A fine dark line 

 defines the front margin of the scuta on these segments. Dorsally at the base of 

 segments 3-8 there is an area densely clothed with coarse bristles, concolorous with 

 the body. The ventral surface of the abdomen is glabrous. At the tip of the body 

 are four rather small laminate appendages which are margined with ferruginous. 

 The larger upper pair lies in a transverse plane, the lower pair is turned obliquely 

 downward. 



Explanation of Plate VI. 



Metriocnemus knabi Coq. 

 Fig. 1. Larva. 

 Fig. 2. Antenna of larva. 

 Fig. 3. Mandible. 



Fig. 4. Labial plate, hypopharynx and labrum (a part of the overhanging dorsal 

 surface of the labrum is seen above). 



Fig. 5. Ninth and tenth abdominal segments of larva. 



Figs. 6-1 1. Hooks of posterior prolegs. 



Fig. 12. Pupa in its gelatinous case. 



Fig. 13. Tip of pupal abdomen, dorsal view. 



