170 \i;\v YOKK STATK MISKIM 



the next small, the following ones again, slender and elongate, 

 the last oin- small; these are all only thinly haired itig.:5j. The 

 eyes round, bare, the ocelli wanting (or rudimentary?!; front 

 broad. The arching of the thorax gradually becomes greater 

 from the head backward, the transverse ^mure wanting: scutel- 

 lum short but wide; metathorax moderately large. Abdomen 

 8-jointed, hypopyginm somewhat projecting. Legs long: coxae 

 not elongated, the fore femora shortest, the posterior pair long- 

 est ; tibiae without spurs; tarsi of the posterior pair of legs ex- 

 tremely slender, and at least as long as the femora and tibiae 

 taken together, the metatarsus about twice as long as ihe follow- 

 ing joints taken together, apical joints small, the sole of the clawed 

 joint bristly, the claws quite long and bent; the halteres promi- 

 nent. Wings long and narrow: venation as shown in tigs. 1 and 1*. 

 The first figure is from V. d. \Vnlp i ls77i the second after Meigen 

 (1818). No North American species ha\-' lieen described. 



Genus 31. Hydrobaenus Fries 



Yrtensk. AUad. Ilandl., 1829. 176. 1830 

 I'-ilnr.Tiis Kutht'. Isis. XI. l'J07. 1831 



i I'l.::i. \\z<. "J to 11) 



Fries i isi'.ih describes the larva and pii|ia at considerable length 

 and gives figures illustrating details of each; the latter are repro- 

 duced on pl.:tl. tigs, i' to ." and 8. 



Larva. The larva is described as being 4 mm. in length, green- 

 ish in color, quite slender, and cylindrical. The head (fig.2) is 

 small, obcoi dale and black. The antennae are three-jointed. On 

 the ventral side of the tirst thoracic segment is a pair of feet with 

 setae (fig.3). <)n the dorsal surface of the eleventh abdominal 

 segment are two cylindrical processes, the extremity of each with 

 a tuft of long hairs. On the ventral surface of this segment are 

 the blood gills, two in number and shorter than in Chirono.- 

 m u s. The twelfth segment has the usual anal feet and four blood 

 gills, the latter, however, differing from C h i r o n o m u s in hav- 

 ing at the apex of each a little tuft of hairs. 



Pupa. (Figs. 5 and 8) Thorax with short and narrow respira- 

 tory tubes. The caudal end is provided Avith two tufts of long 

 hairs. The species shown by Fries is H. lugubris, an 

 European species. 



Imago. Very small black species, the males as well as the 

 females of which have the antennae with short hairs. Ilead small, 



