No. 2.] EXTRAORDINARY NEW MARITIME FLY. 85 



essentially as in male, with, however, appreciable differences in 

 shape ; the labrum-epipharynx is narrower at base, and is more 

 pointed apically ; the labium with paraglossae separated farther 

 back and slightly narrower. The reduced wings and halteres 

 like those of male, the wings, length .85 mm., slightly longer. 

 The abdomen consists of nine segments mottled blackish, with 

 conspicuous white sutural spaces, caused by the distention of 

 the abdomen. The external genitalia are inconspicuous. There 

 is a short emarginate dorsal plate with rounded tips and a pair 

 of small lateral processes. There appears to be no extrusible 

 ovipositor. 



Pupa of Female.-- Among the many specimens collected 

 by Mr. Brown, I find a single female pupa. This specimen 

 throws the only light upon the condition of the immature life 

 of the fly that we yet have. The pupa is of that simple unpro- 

 tected, unmodified type characteristic of those flies, like the 

 Cecidomyidae and Mycetophilidae, whose pupae are protected 

 by lying enclosed in plant tissue. There are no projecting 

 breathing tubes like those of the aquatic pupae, and it would 

 seem that the pupa was quite unfit for an aquatic life. And 

 yet Mr. Brown took this pupa with the imagines from the sur- 

 face of a tide pool. There is a puzzle here. The pupa may 

 be described as follows : Length 2.5 mm. (as large as adult 

 female). Immediately recognizable as pupa of the female 

 from the similarity in size, shape, and markings. Abdomen 

 just as in adult both as regards size, shape, color, and markings. 

 The antennae, legs, and wings are folded on the lateral and 

 ventral aspects of the anterior part of the body and extend 

 backwards only to (hardly reaching) the posterior margin of 

 the second abdominal segment. There are no external tra- 

 cheal gills or elongated spiracles (breathing tubes). There are 

 no bristles nor special clinging organs. The pupa is of a very 

 simple, unmodified, unprotected type. 



The "extraordinary ' features of the external structure of 

 the fly are the condition of the wings and halteres. The con- 

 dition of the antennae and the empodium is also unusual. The 

 reduction of the wings and loss of flight are accompanied by a 

 reduction of the halteres, the flight-directing (?) organs. The 



