222 Mr. F. W. Edwards on 



me Han, longitudinal ri l;:^e ; tibiae finely spiiialose; aaterior 

 feniora incrassated wit)!! tliree prominent spines beneath at 

 apex. 



Long. 17 mm. 



Hub. South India ; Coiinbatore {T. V. Gamphell). 



Si/ncrotHS ciratmscriptaSf Bergr. Proc. Roj. Soc. Vict. vii. 

 p. 293 (1895). 



Bergrotii descril)ed this genus and species from a ? or 

 ? specs., and liis description requires some emendation. In 

 the male the membrane readies the abdominal apex and is 

 considerably smaller than the other sex. " Rufo-cast meus " 

 cannot be accepted as tlie prelominaiit col )nr as stated l)v 

 Bergroth, for the head and pronotuni, in some cases the 

 anterior lobe only, are black. 



Long,, (J 6, ? 9 mm. 



Hub. Queensland; Kuranla {F. P. Dudd). 



XX. — Some Partlienogenetic Cliironomidse. 

 By F. W. Edwards. 



So far as our present knowledge goes, parthenogenesis is of 

 somewhat rare occurrence among the Diptera, but several 

 instances of it have already been recorded in Chironomidse, 

 in the genera Tanijtarsus and Corynoneura. In the case of 

 Tanylarsus the first observations were made by Grimm in 

 1870, and have more recently been confirmed and extended 

 by Zavrel {vide Bause, Archiv fiir Hydrobiol., Suppl. Bd. ii. 

 1913, p. 17). The observations of both these writers 

 concern the rare phenomenon of pupal parthenogenesis. 

 Zavrel found that in the summer broods of Tanytarsas 

 boiemicus, Kieff. MS., eggs could be produced partheno- 

 genetically either by the pupa or by the imago very shoitly 

 after eniergtuce ; the pu|:8e were often found fioating dead 

 ou the water full of developing eggs, from which larvae 

 eventually hatched. In all cases the adults reared from 

 such larvse proved to be females. 



Another case of partheni genesis — in this instance of a 

 more normal type — has been recorded by Goetghelmer as 

 occurring in Carynontura ccleripes, Winn. (Bull. Acad. Roy. 

 Belg. 1913, pp. U31-.233). This author was aljle to rear 

 three successive generations of parthenOj^enetically ])roduced 

 cggs^ which in every case yielded female adults. 



