PXrCHOPTERA. 279 



In the practical absence of the peculiar fold in tlie wing which 

 I have elsewhere termed the " obliterative streak," |)assiug from 

 the stigma to beyond the discal cell, the Ptychoptekij^^.I:: approach 

 the LiMNOBiiN.i;. In possessing sixteen joints to the antennae, 

 this subfamily also agrees with the Limnobiix.i;, but Ftychoptera 

 and at least one other genns {Bittacouioiyha) possess a sHght pro- 

 longation of the epistoma into something like the nasus of the 

 Tipulin.t:. Ftiiclioptera also rests with its wings divaricate, as 

 do most of the latter subfamily. 



The difference in the number of the antennal joints is com- 

 paratively unimportant, considering the variation in this character 

 which occurs amongst the Limnobiin.e. 



In venation the Pxychoptbrix.e show considerable variation. 

 A discal cell is sometimes present {Idioplasta, Os, Sac, Tamjderus, 

 Phil., 2Iacrocliile,Jj\\ .), or absent {Pdjclioptera, Mg., Bittacomorpha, 

 Westw.). (^ne genus {Idioplasta) has no less than six posterior 

 cells, the normal number in the subfamily, however, being three 

 or four. 



Beyond Ptychoj^tera (of which only three species are known 

 from the East) only one other species of this family is Oriental — 

 Tanyderas oniatissimus, Dol., from Amboina. 



The larval characters of the Ptychopxeiiix.e have been investi- 

 gated by Brauer,* and that biologist considered that as the head 

 of the larva is not imbedded in the thoracic skin, as is the case in 

 the rest of the Tipulid.e, it is justifiable to separate the group as 

 a distinct family. Osten Sacken has also referred to the same 

 subject.f 



Genus PTYCHOPTERA, My. 



Pti/ckoptera, Meio-en, lUig. Ma-?, ii, p. 262 (1803). 



? Ctenoceria, Rondani, Dipt. Ital. Prod, i, p. 187 (1856). 



Genotype, Tipida contamiaata, L. 



Head transverse, with rather prominent, round, bare eyes. 

 Epistome well arched, nearly perpendicular, terminating in a blunt 

 point. Frons broad in both sexes, flattened. Ocelli wholly absent. 

 Proboscis prominent, with round pubescent iabella. Palpi elongate, 

 slender, four-jointed, the last one the longest, but not so con- 

 spicuously longer than the others as in the Tipulix.e. Antennae 

 IG-jointed, long, prominent, slender, nearly bare ; scapal joints 

 short, the 1st longer than the 2nd ; flagellar joints cylindrical, 1st 

 joint considerably longer than the others, which gradually diminish 

 in length, apical joint sometimes indistinct. Thoraj- prominently 

 arched, suture almost imperceptible. Scutellum small, metanotum 

 well developed. Abdomen elongate, often narrowed in middle, 



* Verb, zool.-bot. Ges. Wien, 1869, pp. 844-847. 



t Cat. North Amer. Dipt., 1st ed., p. 221, note 36 (1878). 



