168 C. R. Osten Sacken: 



circumstances. Specimens of the genera of the first couple were 

 found nearly in the saine locality, and at the same season in the 

 Cevennes. We have a right to suppose therefore that their larvae 

 lived in the running waters of tliat region. In the same way the 

 larvae of Cnriqrira and Snotvia were found promiscuously in the 

 waters of Southern Brazil. Dr. M. says: The two sexes seeni to 

 occur in about equal numbers. One day, from 70 pupae I extracted 

 20 males and 20 females, and of these 13 had small eyes, short claws 

 and no mandibles, whereas 7 were provided with mandibles, and had 

 large eyes and long claws." (Dr. F. M., Ent. M. M. XVII, p. 225, 

 March 1881). Bleph. and Lip. differ principally in the structure of 

 the head; in other respects they are closely related to each other 

 in the venation, and other characters. Just the same relation exists 

 between Carup. and Snowia, although as I have said above, they 

 belong to another group of the family: like the first couple they differ 

 principally in the structure of the head, and agree in the venation 

 etc. The difference, however, between the cases of the two couples 

 consists in the fact, that the genera of the European couple are known 

 in both sexes, while the two genera frora S. America, are known in 

 one sex only {Curup. c/, Snotvia 9), and that there is a second 

 flowersucking form of female of still uncertain position, connected with 

 the second couple. Whether these evident coincidences between two 

 cases of a promiscuous occurrence of two different, although closely 

 related genera are merely fortuitous, or foreshadow some unexpected 

 discovery of a hitherto hidden connection between them, remains to 

 be Seen. 



It has often been noticed that remarkable scientific discoveries 

 were made almost at the same tinie in different places, and inde- 

 pendently of each other. Such is the case with the discovery of the 

 most anomalous forms of Diptera: The enigmatic Scenopinus was 

 described by Latreille 1802, and, in the next year 1803 by Schrank 

 as Airichia, by Meigen as Hypselura, and by Schellenberg as 

 Cona. The refractory Orphnephila was described by Haliday in 

 1831, and in the same year, as Thaiimalea, by Ruthe; three 

 years later by Macquart as Chenesia. The first Blepharocera Q 

 was discovered by Mr. Arnaud in June 1841, and the first Lipo- 

 ne^ira cf by him in 1842. Westwood in 1842 described his Asthenia, 

 from Albania, on the Balkan Peninsula; the exact date and the author 

 of the capture are not given. Loew, bcfore he knew anything about 

 the publications of Westwood and Macquart, published the genus 

 Liponeiira (1844), which he had receivod from Silesia (perhaps from 

 Zeller V). Finally, the descriptions of the anomalous larvae of the 



