1918] Aldrich—Nofes on Dipfera 31 



began in 1904, there was no such opportunity for the flies to be 

 carried, as the trains did not run close enough to the water. 



That the species is not indigenous to San Francisco Bay is fairly 

 well demonstrated by the following facts: (1) It was not in the 

 Stanford University collection, which is rich in local Biptera, the 

 accumulations of many years, and is only about ^| miles from the 

 place where I recently found the species; i'i) It is not in the col- 

 lection of the University of California, although a few years ago 

 an advanced student, Burle R. Jones, made and published a special 

 study of California Ephydridse, for which he collected extensively 

 about the Bay (Catalogue of the Ephydridse, etc. Technical 

 Bull., Cal. Agr. Exp. Station, 1908) ; (3) It is not in the collection 

 of the California Academy of Sciences, nor was it in the old col- 

 lection destroyed by fire in 1906, as I personally know from exam- 

 ination; (4) In 1905-6 I collected repeatedly along the Bay near 

 Palo Alto, and visited the same place again once in 1911, without 

 finding the species. 



As a matter of fact, up to the present report there have been 

 only about half a dozen specimens of the species ever found away 

 from Great Salt Lake; these are from Yuma and Salton Sea in the 

 National Museum, one from Laguna, Cal., taken by C. F. Baker, 

 and one from "S. Cal." which Jones made the type of Ephydra 

 cinerea. The last two, which I have studied, are larger than the 

 average but not larger than the largest specimens from Great 

 Salt Lake, and the same is true of the 18 specimens I secured near 

 Palo xVlto last summer. This perhaps indicates that the extreme 

 density of the water in Great Salt Lake exercises a dwarfing in- 

 fluence upon the species. 



(b) When Van der Wulp described Charadrella macrosoma new 

 genus and species, from Northern Yucatan (Biologia Cent.-Amer., 

 Dipt., ii, 341, 1896), he added the following note: 



"As the fourth vein is not curved, but runs directly to the tip of 

 the wing, this genus is included here among the Anthomyinse; 

 on account, however, of the presence of a perpendicular row of 

 macrochaetse on the hypopleurse, before the halteres, it would not 

 belong to the Anthomyinse in the sense of Girschner's system of the 

 Muscidae Calypterae." 



An Anthomyid with hypopleural bristles would be anomalous 

 indeed, and I have long desired to see the species. The desire was 



