26 



always the marsh-bred varieties of Oulex. Besides, the examination 

 of at least a thousand mosquitoes on Ship Island has convinced me 

 that there are no Stegomyia here. 



Each vessel inspected was carefully searched, the inspector being 

 armed with a cyanide killing bottle, and in additiojh the captain was 

 asked the following questions: 



1. Were there any mosquitoes on board on your outward voyage, 

 consisting of days? 



2. If so, did they come aboard before departure from home port or 

 at sea, and under what circumstances ? 



3. Were there any mosquitoes on board at your destination or on 

 homeward voyage ? 



4. If in port — 



(a) How far were you from shore? 



(b) Prevailing wind and weather ? 



5. If on homeward voyage (consisting of days) — 



(a) Were they from port? 



(b) Did they come aboard at sea, on what day, and how far were you 

 from land ? 



(c) Were there wigglers in any of your tanks at any time? 

 During the five months from June 1 to November 1 observations 



were made on 82 vessels, all arriving from ports where the Stegomyia 

 is believed to exist in quantities. Of these 78 were sailing vessels 

 and 4 were steamers. 



Of these 82 vessels 65 claimed to have had no mosquitoes aboard at 

 any time during the voyage or at port of departure, and their absence 

 having been confirmed by search, we .can dismiss them from consider- 

 ation and pass to the remaining 17. 



Five of these had mosquitoes on board at their ports of departure, 

 2 being rid of them as soon as they were well at sea, while 3 others 

 carried' them two days and were then no more troubled, except one 

 schooner on which they reappeared in quantities five days before she 

 reached this port, when she was 20 miles from shore. 



Nine sailing vessels, having no mosquitoes on board before sailing, 

 had them appear at sea, in one case from the water casks in which the 

 captain found larvse. But in the other cases they doubtless came from 

 land which was at the time distant — 20 miles in one case, 15 miles in 

 three cases, 10 miles in one case, and 2 miles in the last two instances. 

 In all these vessels the mosquitoes found on board on arrival at this 

 station were the common varieties of Oulex, there being no Anopholes 

 or Stegomyia among them. 



Stegomyia fasciata were found on board and were identified in the 

 remaining three cases, as follows: 



The schooner Susie B. Dantzler arrived from Vera Cruz, Mexico, 

 on July 16, 1902, after a voyage of fifteen days. The captain stated 



