272 



Pupa. — Length, 2.5-3.5. Prothoracic respiratory organ very 

 similar to that of minuta, the openings of tracheae paired to base; 

 apices of hind tarsi projecting very sHghtly beyond apices of wings. 

 Armature of abdominal segments similar to that of sitpcrba but dis- 

 tinctly weaker, especially on apex of second dorsal segment, where 

 the spinules are not well defined ; apical segment with both the upper 

 and lower pairs of apical thorns rather strong, the armature as in 

 Figure 3, Plate XXXIX. 



The foregoing descriptions are drawn from larvae and pupae 

 which T obtained from a water trough in the dark room of the labo- 

 ratory here in June, 19 16. The pupal stage lasts from 3 to 5 days. 

 The trough is not properly leveled, and along one side a small amount 

 of water periodically accumulates which because of its unfiltered con- 

 dition is soon permeated with an algal growth, in which the larvae 

 feed. 



Haseman's figure of the larva of doiiicstica does not show the 

 plates on the second abdominal segment. His description indicates 

 that he found some variation in the number of plates on the basal 3 

 segments. My material does not show any variation. 



Muttkowski's figure of the larva of cincrea does not show the dor- 

 sal hairs, but probably he overlooked these. 



PSYCHODA ALBIMACULATA Welch 

 Fsychoda alhimaculata "Welch, Ann. Ent. Soe. Anier., Vol. 5, 1912, p. 411. 



Full descriptions of the larva, pupa, and imago are given by Welch 

 in the paper above cited. 



I have before me the same stages, obtained in the reservoirs at the 

 35th street pumping-station in Chicago. Welch's material came from 

 the same reservoirs. 



PsYCHODA sp. ? 



Larvae of a species closely allied to doincstica were obtained from 

 a wound in a mulberry-tree, from which sap was exuding, at Urbana 

 in July, 191 5. My material is not plentiful enough to permit a defi- 

 nite decision regarding the specific identity of the species. A figure of 

 the larva is given herewith (PI. XXXIX, Fig. 14). 



References to descriptions of immature stages of other North 

 American species are given in the following list of notes and papers, 

 the species dealt with being placed 'in parentheses in each case. 



