3. OXYCERA 87 



{i.e., light brown and dark brown) between the two sets of facets. Antennae moderately 



long, with the two basal joints almost equal in length, but the third joint (or 



flagellum) peg-shaped and with four annulations followed 



(except in 0. tenuicornis) by a two-jointed subapical bristle 



(fig. 107), which bears at its tip a microscopical filament-like 



arista. 



Thorax oblong, rather arched, Avith the humeri and the 

 postalar calli prominent. Pubescence fairly dense but not very 

 conspicuous, and leaving a large triangle on the mesopleurse 

 bare and polished. Scutellum with one conspicuous pair of 

 subapical spines. 



Abdomen short and almost rounded, strongly arched, and 

 with five obvious segments. p^^ ^^.j. _ 



Legs simple. _ _ Oxycera pulekella <i . x 32. 



Wings (figs. 108 and 109) with the normal venation of the 

 Ciitellarince. Cubital vein with or without a fork; discal vein faint, and the 

 discal cell emitting three veinlets towards the wingmargin of which the third is 

 often missing, and liesides these three tlie upper branch of the postical vein appears 

 to issue from the discal cell close to the second basal cell because there is no small 

 cross-vein, and consequently the upper branch of the postical vein forms for a short 

 distance the lower margin of the discal cell ; none of the veinlets issuing from the 

 discal cell nor the upper branch of the postical fork reach the wingmargin ; wing- 

 membrane rippled, very minutely but very densely pubescent. A-lula well de- 

 veloped. Squamae (alar) moderately well developed, but the thoracal pair practically 

 absent or represented by a small or large long fringed lobe. 



This genus is well distinguished from the rest of the Palsearctic 

 ClitellarinoG by its armed scutellum, and by the comparatively short 

 antenuEe which have a short basal joint and a subterminal arista (except 

 in 0. tenuicornis). The Central-American genus Aochletus must be almost 

 if not quite inclusive of 0. tenuicornis, as Osten Sacken says it is " an 

 " Oxycera with a stout terminal joint to the antennae, instead of an aristi- 

 " form style " ; but his statement that Aochletus has after the fourth joint 

 of the flagellum " an elongated body, a little longer than the two preceding 

 " joints taken together, without any distinct articulations, and placed 

 " somewhat at an angle to the axis of the antenna," does not at all 

 agree with 0. tenuicornis ; I have therefore retained that species in the 

 genus Oxycera, with which it agrees in all other characters, especially as I 

 look with suspicion on all genera in the Strcdiomyidce which are formed 

 on the terminal joint of the antenna alone. 



Oxycera is recorded from all Europe, Asiatic Russia, Celebes, 

 Africa (Caffraria), and North and South America, but apparently Europe 

 and Northern Asia form the headquarters of the genus, as about forty 

 species are known to occur there, of which eleven are now described as 

 British and one or two more {0. leonina and 0. Fallenii) are likely to occur. 



The metamorphoses are well known, as Heeger in Sitz. Acad. Wiss. 

 Wien., XX. (1856) has figured and described in much detail the larvae 

 of 0. Meigcnii and 0. trilineata, while Haliday in Nat. Hist. Eev.. 

 iv., 193 (1857) described and figured the larva of (probably) 0. Morrisii. 

 Haliday says that this " larva occurred among the ConfervoB and March- 

 " antia on the face of a dam serving for an outlet to the superfluous water 

 " of a mill-race, and continually moistened by a shallow but rapid fall of 

 " running water " ; he considered the larva allied to Neniotelus. I have 

 usually taken the perfect insects by sweeping in the neighborhood of 

 water or marshy ground, though I have seen 0. pukhella on the leaves of 

 shrubs. 



