212 Papers from the Department of Marine Biology. 



arenaria, whose carapace measured 1^ inches, was set under bay cedars 

 near the beach and several specimens representing both species of flies 

 were inclosed by means of a cover of fine bolting cloth. Within the 

 next 2 days all the adults died and none was seen inside the jar until the 

 morning of July 29, when three imagoes had emerged. On examination 

 101 pupae were found near the bottom of the sand; the majority were 

 of the larger species. It is thus evident that, if 104 maggots of a fly 

 the size of the house-fly can develop to maturity within a single small 

 crab, it is not necessary to look to migrations to keep up the stock of 

 adults at Tortugas. To be sure, the large number of ants there may 

 be relied upon to keep the flies within bounds ; very few dead crabs are 

 left long above ground. But years ago a former keeper of Loggerhead 

 Light, Mr. George Billbury, called Dr. Mayer's attention to the 

 fact that certain flies were to be noted about the entrances of crab 

 burrows in the sand. As he surmised at that time, it is very possible 

 that these flies may occasionally breed in crabs which, for some reason, 

 die in their burrows. 



SUMMARY. 



1. Large numbers of mosquitoes and house-flies are carried by 

 northerly and southerly winds to Rebecca Shoal light-station and the 

 Tortugas Islands from Florida and Cuba. 



2. Easterly winds bring a few of these, as well as smaller numbers 

 of blow-flies, horse-flies, and gnats from islands east on the Florida Reef. 



3. Occasionally Odonata, Neuroptera, and Lepidoptera are carried 

 by the winds to these parts of the reef. 



4. Sarcophagidse breed in land crabs at Tortugas. 



BIBLIOGRAPHY. 



COQUILLET, D. W. 1905. A classification of the mosquitoes of North and Middle America. 



Technical Series No. 11, Bureau Entomol., U. S. Dept. of Agric. 

 GILES, GEORGE M. 1900. A handbook of the gnats or mosquitoes, xi+374 pages. 

 HOWARD, L. O. 1901. Mosquitoes, xvm+241 pages. 



., HARRISON G. DVAR, and FREDERICK KNAB. The mosquitoes of North and Cen- 

 tral America and the West Indies. In 4 volumes. Octavo. Carnegie Inst. 

 Wash. Pub. No. 159. 

 Vol. 1. A general consideration of mosquitoes, their habits and their relations to 



the human species, vii+520 pages, 14 plates, 6 text figures. 1912. 

 Vol. 2. x pages, 150 plates. 1912. 



Vol. 3. Systematic description, Part I. Pages vi+523. 1915. 

 Vol. 4. Systematic description, Part II. Pages 525 to 1064. 1917. 

 MITCHELL, EVELYN G. 1907. Mosquito life. 

 SMITH, J. B. 1904. Report of the New Jersey State Agricultural Experiment Station 



upon the mosquitoes occurring within the State, etc. 482 pages. 



THEOBALD, F. V. 1901. A monograph of the Culicidse of the world. Vols. 1 and 2, 

 British Museum. 



