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Some Insects of the Between Tides Zone. 



Charles H. Akndt. 



All insects, except a few species which live entirely in the water and 

 have functional gills, are air breathing animals, breathing by means of 

 tracheae. Thus we may desire to know how air breathing insects living 

 in a zone which is submerged twice a day, prevent themselves from being 

 drowned ; or, if breathing by means of gills, they protect themselves from 

 superoxygenation during the low tide. We may further be interested in 

 any adaptations, or unique instincts, which make the inhabitants of such a 

 locality especially adapted to their environment. 



The following observations on the habits of the insects of the between 

 tides zone, were made in the region directly north of Jones' bath house 

 at the head of Cold Spring Harbor Bay ; which is included in the lines 

 drawn from 600 E., 200 S., to 200 N., 40O E ; and 20O N., 800 E., on map 

 of Inner Harbor made by Johnson and York. Many observations were 

 made on the extreme outer limit of the Spartina cynosuroides 275 N., 

 400 E. The slope of the shore to the west of the boat landing from 

 the outer limit of the Spartina to within two feet of the inner limits 

 of the Spartina is about 6%. From the latter point to the inner limit of the 

 Spartina the slope is more abrupt. The Spartina is here replaced by a short 

 (about six inches high), densely matted grass, Juncus Geravcli. This covers 

 the entire region around the bath house with the exception of a few pebble- 

 covered areas on which there is a sparse growth of Spergularia Marina. 

 (Map 2.) 



The highest tides of the summer, July 8, 9.2 feet; August 3, 8.8 feet; 

 submerged the region as far as the bath house. From July 11 to July 

 29 the Spartina area was never entirely submerged, due to the low tides 

 and the absence of any strong easterly winds. The observations extended 

 from July 1, to August 5, 1913. 



