322 INSECTA. 



LiMNOBiA, Meig., 

 Where the wings are glabrous, and the antennae simple in both 

 sexes *. 



The PoLYMERA of M. Wiedemann — Dipt. Exot., p. 40 — appear to 

 be distinguished from the Limnobice by iheir antennae, which con- 

 sist of twenty-eight joints, instead of from fifteen to seventeen. 



In the other subgenera, the antennce are terminated by several 

 joints, evidently more slender, and almost cylindrical. 

 Trichocera, Meig. 

 The first joints of the antennae almost bordering on an oval, the 

 following ones more slender, long, and pubescent. 



The Tipule d'hiver of De Geer, Avhich resembles a Calsx, 

 belongs to this subgenus f- 



Macropeza, Meig. 

 The Macropezae are distinguished by the extraordinary length of 

 their posterior legs. Their antennse, to a little more than half their 

 length, are densely pilose ;]:. 



DixA, Meig. 

 The Dixae are apparently closely allied to the Trichocera?, but the 

 first joint of their antennae is very short, the second is almost glo- 

 bular, and the following ones are proportionally more slender. The 

 last joint of the palpi is also more elongated than in Trichocera §. 

 There the autennre have but ten or six joints. 

 Those, in which they consist of ten, form the genus 



M.EKisTOCERA, Wied., 

 Where the wings are distant |j. 



Those in which they are composed of six form the 

 Hexatoma, Lat., 

 Which will com.prise the Anisoinerce and Nematocerce of Meigen, 

 Avhich only differ from the Hexatomra by the third joint of the an- 

 tennse. being there longer than the second : in this respect it differs 

 but slightly from the others % 



Other Tipulariae, analogous to the preceding ones in the absence 

 of ocelli, and the rounded figure of their eyes, exhibit a rare anomaly 

 in this order of Insects : they are destitute of wings, and hence the 

 orip-in of the term Aptera, which wc apply to this subdivision. The 

 antennae are filiform, but somewhat more slender tov.'ards the extre- 

 mity, and but slightly pilose. The legs are long, and the tibiae 

 unrumed. The abdomen of the females terminates in a point formed 

 by a bivalve ovipositor. 



This subdivision comprises the genus 



* See Meifr., Dipt. I, 155.; Lat., Gen. Crust, et Insect., IV, 254; but after 

 removing the Pedicije. 

 t Sec Meig., Ibid. 

 X Idem. 



§ Meig., Ibid., and Macq., Dipt, du nord do la Fiance, 

 il Dipt. Exot., p. 41. 

 'i Lat., Gen. Crust, et Insect,, lY, 260; Meig., Ibid. 



