228 [October, 



ON A DISTINCTIVE CHARACTER OF THE IMAGOS OF THE SUB- 

 ORDERS OF DIPTERA: ORTHORRHAPHA BRACHYCERA and 

 CYCLORRHAPRA ATIIERICERA, INTRODUCED BY LATREILLE 

 (1825), BUT OVERLOOKED BY LATER AUTHORS. 



BY C. R. OSTEN SACKEN, Ph.D., Hov. F.E.S. 



Latreille (Families Naturelles, 1825, p. ISO) defines the mouth 

 parts of the Orthorr kapha Brachycera (a compound of his Fam. II, 

 Tany stoma, and Fam. Ill, Notacantlut) as follows: — 



" 1. — lei, le sucoir et les palpes sont inseres tres pros de l'origine 

 de la trompe, a l'entree de la cavite buccale ; cette tromj)e, ou du 

 moins les levres, forment ordinairement une saillie hors de la cavite." 



The corresponding passage, concerning the Cyclorrhapha Atheri- 

 cera (Latredle's Fam. IV, Aiherieera) is found in the middle of p. 494, 

 aud runs as follows : — 



" 2. — Dans les autres Dipteres, le sucoir et les palpes sont inseres 

 a une distance notable de la cavite buccale, pres du coucle de la trompe, 

 qui est entitlement retiree dans cette cavite, ou saillante, et en forme 

 de siphon, mais dont le sucoir n'est jamais alors compose que de deux 

 pieces." 



The dipterologists of the second half of the XlXth century 

 have too much neglected the publications on Diptera of the great 

 Latreille. In my paper, " On the characters of the three divisions," 

 etc. (Berl. Ent. Z., 1892) I have shown (on pp. 421 and 422) that 

 Loew, Brauer and other entomologists had considered the number of 

 the joints of the antenna as the only character separating the Nemo- 

 cera from the Brachycera ; they were quite prepared to give up these 

 Suborders when Rhachicerm, the multiarticulate genus of Brachycera, 

 was discovered, and when it was noticed at the same time that other 

 genera of Brachycera, as Xylophayus, Subula and Ccenomyia* also had 

 multiarticulate antenna?. Brauer especially was most emphatic in 

 this sense, lie said, " Mogen die Dipterologen, der Bequemlichkeit 

 wegen, auch heute noch von Nemoceren. und Brachyceren sprechen, 

 derlei naturUche Gruppen giebt es nicht, und man ist auch nicht im 

 kStaude natiirliche Charactere fiir sie aufzustellen " (Brauer, Zweifl. 

 d. K. Mus. Wien, iii, p. 9, 1883). 



1 pointed out in my above quoted paper of 1892 (ou pp. 419-20) 



* I am thoroughly convinced that Caenomyia, and not the commonly used form Coenomyia, is 

 the right spelling of this generic name. My reasons are : — 1". It is quite distinctly spelt Coenomyia 

 in Latreille's principal work, Genera, &c, 1809, vol. iv, p. 280; 2°. Its derivation from the Greek 

 Kaivos, new, extraordinary, is much more probable, and more appropriate to this very peculiar 

 Dipteron, than that of kolvo<;, common, ordinary. The mis-spelling Coenomyia, as it occurs every- 

 where, even in Latreille's other works (Precis, 17'JG ; Earn. Natur., 1825), is merely due to the 

 confusion of at and oe in print, easily overlooked by proof readers. 



