318 ENTOMOLOGICAL NEWS. [J a n 



to the quick perception of moving objects. But what makes 

 this explanation less convincing is the fact that the males also 

 possess these large faceted ommatidia, although, to be sure, in 

 fewer number. Perhaps both males and females are active at 

 twilight. Search as carefully as I might I could never find 

 but very few of the adult Blepharocera along the stream, from 

 which they were certainly issuing by thousands. Until the 

 habits of our fly is better known, then, it is hardly profitable 

 to speculate on the special use of its large faceted eyes. 



In closing I wish to call attention to three other accounts of 

 the life-history and structure of Blepharoceridie, one being a 

 paper (in Russian, which I have not seen) by Wierzeijskii ; * 

 another a description of the larva and pupa of Liponeura brev- 

 irostris, the specimen being found near Goslar, in the Hartz 

 Mountains, Germany ; the other a detailed account (in Portu- 

 guese) of the structure of the larva, pupa and imago of Palto- 

 stoma torrentium, found in the province of Santa Catharina, 

 Brazil. f In this last account Dr. Muller claims that the females 

 are dimorphic, one kind of female having divided eyes, man- 

 dibles and long tarsal claws ; and, being blood-sucking in 

 habit, while the other kind lacks the dorsal large faceted eyes 

 and mandibles, has short tarsal claws and is nectar- suck ing in 

 habit. Baron Osten Sacken has not been able to satisfy himself 

 that Muller is correct in his claim of dimorphism, despite the 

 fact that Muller's reiterations are very emphatic. With this 

 question of dimorphism in mind I have examined all of the 

 females of Blepharocera capitatawlaicb. I have collected, twenty- 

 three in number. All these females agree in possessing dorsal 

 large faceted eyes and mandibles, and agree in all other struc- 

 tural characters. There is no dimorphism among these speci- 

 mens. Now almost all of the specimens were taken just 

 at the moment of issuance from the pupal case in different 

 parts of the stream at different times. The criticism that one 

 kind of female may have habits rendering it more easily dis- 

 covered and captured than the other kind, and, hence, that 

 my few specimens include only the easily taken ones, is not 

 valid in this case. I have, beside, dissected or sectioned many 

 pupa?, and, in the case of all females thus examined, the 

 mandibles were present. It seems probable to me that there is 

 no dimorphism among the females of Blepharocera capitata Low. 



* Dewilz, H. " Beschrei bung der Larve u. Puppe von Lipoueura, 

 brevirostris Low," Berliner Eut. Zeitsch., vol. xxv, 1880, pp. 61-66, 

 pi. Iv. 



t Muller, Fritz. "A Metamorphose de um lusecto Diptei-o,'' 

 Archives do Museu Nacioual do llio Janeiro, 1881, vol. iv, pp. 47-85 

 pi. Iv-vii. 



