152 C. R. Osten Sacken: 



is much less distinct, and less developed in its details; it justifies 

 Schiner's (Nov. jj. 28) likening it to a delicate spider's web. Never- 

 theless a close comparison reveals a conformity of the principal lines 

 of the net in the two species. — Halida^-, in an Appendix to Loew's 

 paper (in the Bullet, etc. 18G9, p. 99) is the only one who paid sonie 

 attention to this secondary net. But he started from a false premisc. 

 founded upon the imperfection of Schiner's figure of the wing of 

 Paltostoma (Novara Tab. II, f. 4). The seventh longitudinal (axillary) 

 vein in that figure is represented by a line of the same thickness as 

 the lines of the secondary net. Haliday concluded from it that 

 this vein was nieant for a line of the secondary net, and as a re- 

 presentative of the primary axillary vein which was wanting („dove 

 la vena longitudinale ultima e semplice [che succede alla vena bi- 

 forcata nelia Blepharocera ecc], mancando nel sistema delle vene 

 primarie, si trova perfettamente rappresentata nella reticella secun- 

 daria"). But this supposition is easily set aside by a reference to 

 Schiner's letterpress (Nov. p. 28, line lo) where it is distinctly said: 

 „Axillarader deutlich und ziemlich lang." The thinness of the axillary 

 vein is therefore a defect in the figure. The genus Curiipira F. Müll., 

 allied to Palt, and represented as having the same venation, is figured 

 with a very distinct axillary vein (Dr. F. Müll., 1881, Tab. VIT, f. 7). 



A. Charaeters belongiiig to all the geiiera. 

 Wings. Nu discal cell. Venation gradually degraded from ninc or 

 ten longitudinal veins (Bihioc, Agathon), to only four or five 

 veins {'HammatJ. 

 A secondary net of crease-like lines on the wings. 

 Peculiar shape of the wings, with a large, angular anal lobe. 

 Alula, tegula and antitegula absent, or rudimentary. 

 A small chitinous thickening in the axillary incision (I have 

 observed it in all the species which I have seen; comp. O.S., Berl. 

 Ent. Z. 1892, p. 455. It has not been noticed by any other author). 

 Streng iridescence of the wings which, in some species (Lipon, 

 yosemite, Lip. hrevirostris, Hapalothrix) shows a beautiful 

 violet-blue opalescence. 

 Eyes of a nearly identical structure in both sexes (that is, either 

 holoptic or dichoptic in both sexes; the same identity in the 

 case of bisection by a groove). 

 NB. In Blephar. ca^ßitata I noticed that the portion of the eye above 

 the bisecting line is a little sra aller in the male than in the 

 female (0. S. 1878, p. 405). I do not know whether a similar 

 diifereuce occurs in other species. 



