456 Osten Sacken: on the char acters of the three divisions of 



aboiit Liponeura: „the digestive tube was tillcd with black matter, 

 apparently nothing but mud and slime"). They brcatlie by mcans 

 of bunches of tracheal branchiae on each side of the segments of the 

 body. The larva oi Liponeura is remarkable for its long antennac; 

 that of Paltostoma has much shorter ones. The pupa is protccted 

 by a tortoise-like flat roof, fastened to the stone or weed; on the 

 thorax it has a pair of perfoliate branchiae for breathing. According 

 to Fritz Müller the larvae have tive Malpighian vessels, like the 

 larvae of Culex; not four, which is the usual number. i) 



Since 1840 when the tirst Blepharocerid was described, fifteen 

 species have been discovered — six in Europe, one in Asia (Ceylon), 

 six in the United States and Mexico and two in Sonth-America. 

 Their extraordinary characters, their graceful shape, their mode of 

 life, almost exclusively among romantic mountain-scenery, the males 

 dancing in the spray of picturesque waterfalls, all these anomalies 

 and eccentricities lend to this family a peculiar charm. 



ßliypliidae. Rhyplius is a Singular genus, and Loew must 

 have feit it, when he said ( without giving any reason) that he 

 considered it „as standing in a closer relation to the Bracliyce7\i 

 than any other genus among the Nemocera" (Loew, in Nat. Hist. 

 Eeview, London 1856, p. 79). RliypJuis is a stranger among tiie 

 Nemocera vera principally on account of its holoptic head in the 

 male, and its largely developed empodia, which resemble thosc of 

 Scatopse, and look as if the pul villi were connate with thcm. 

 There are three ocelli. The filiform antennae are clothed with hair, 

 but have no distinct verticils. The wings have a discal cell (like 

 the Tipididae among the Nem. vera); the axillary excision is prc- 

 sent, the alula moderately, the antitcgula largely developed; no te- 

 gulae. The larva is amphipneustic, serpentiform. 



The thoracic dorsum shows two rows of dorsocentral, weak, 

 but distinct, little bristles, two abbreviated lateral rows of similar 

 little bristles, some others on the post-alar calli, and two on the 

 apex of the scutellum. These little bristles, in the regularity of their 

 distribution, seem to foreshadow the macrochaetae of other families. 



i) F. L. Arribalzaga, Dipterol. Argent, 1891, p. 13 and 17 found 

 five Malpighian vessels in the pupa aiid imago of Cideoc, and six in 

 the larva. Some Psychodidae (imago) likewise have five Malpighian 

 vessels, but the usual number is four (compare Du four, Rech. anat. 

 Dipt. 1851, p. 213: „j'ai conslate l'existence de cinq vaisseaux ht^pa- 

 tiques, comme chez les cousins, presqu'aussi souvent que celle de quatre, 

 que je regarde comme le nombre normal"). 



