[Berliner Entomolog. Zeitschrift Bd. XXXIX. 1894. Heft II.] 267 



A remarkable case of malformation of the 

 discall cell in a specialen of Liogma glabrata. 



C. R. Osten Sacken. 



In August 1893 I caught in Aussee (Styria) a Tipulid which is 

 undoubtedly Ci/lindrotoma glabrata Schin. II, p. 563 (whether it is 

 the same as Limnobia glabrata Meig. I, p. 142 is probable, but not 

 eertain, as I shall presently show). In this speciinen Ihe discal cell 

 is open. in consequence of the complete disappearance of the cross- 

 vein which separates it from the first basal cell. On both wings, the 

 struetnre is exactly the same, and the adjoining veins forming the 

 discal cell (the posterior brancli of the third vein and the fourth 

 vein) do not show the slightest vestige of a stump or any trace of 

 an obsolescent crossvein. In all my experience with Tipulidae I 

 have never met with a case of disappearance of the crossvein in that 

 place, the more so as this vein-section is not properly a crossvein, 

 but the first section of the anterior brauch of the fork of the fourth 

 vein, which fork, aecording to Schiner's view, encloses the discal 

 cell. An inexperienced entomologist would have easily taken this 

 speeimen for a new genus, although there is not the slightest doubt 

 that it is a malformed glabrata Schin. I have visited Aussee in 

 1879 and in 1893, for the purpose of visiting friends, and not of 

 collecting; still I picked np interosting spednions here and there. 

 Besides the glabrata, marked Aug. 1893, I have a normal speeimen 

 of the same species, labelled July 1879, from which I conclude that 

 glabrata is not rare in that locality (Schiner calls it: „sehr selten", 

 for Austria). 



Meigen's description (I, p. 1-12) must be modified in connection 

 with bis corrigendum in VI, p. 274. Meigen calls the thoracic 

 stripes atrae „tiefschwarz", which is a rather inappropriate term for 

 the shining stripes of glabrata. Nevertheless, the identitication is 

 possible. At any rate, even if the species should prpve not to be 



