149 



nests, uttering angi'y cries at the spoliation of their treasures. After 

 tlie first bird fell into tlie water, tlie others showed the usual sym- 

 pathy of their Ivind, but as the third or fourth specimen was killed, 

 the remainder cautiously withdrew and uttered their complaints at a 

 safer distance. Several other pairs were nesting on the Lake at this 

 time, but we were unable to find their nests. 



308. S. superciliaris Vieill. Least Tekn. A very rare summer 

 visitant in this vicinity. A fine male specimen is in the collection of 

 the Chicago Academy of Sciences, obtained June 11, 1876, upon the 

 Calumet Marshes. 



Genus Hydroehelidon Boie. 



309. H. lariformis Coues. Shokt-tailed Tern. Exceedingly 

 abundant summer resident upon all the large marshes and prairie 

 sloughs. Arrives the first of May and remains until the first of Sep- 

 tember, after which but few are to be found. I have taken freshly 

 laid eggs from May 2oth to June 18th. The middle of June I have 

 taken specimens in perfect winter dress, although this is unusually 

 early. Generally a few white feathers begin to appear near the base 

 of the bill about this time, and by the first week of July an endless 

 series may be seen between the perfect breeding to the perfect winter 

 plumage. By the middle of July specimens iu which the black pre- 

 dominates are i-are. This bird frequentis almost exclusively reedy 

 streams and marshy situations, and is never found upon Lake Michi- 

 gan except during the migrations, when a few specimens may be seen 

 with the flocks of the larger terns. 



The following notes upon the breeding habits of this species com- 

 prise my observations during the last two seasons, during which time 

 I have examined J^etween two and three hundred nests. In nearly 

 every instance the eggs were deposited in a well-built nest formed of 

 the surrounding material. In prairie sloughs the nests are generally 

 located well out from shore, in from one to two and one-half feet of 

 water, and in the midst of the fine wiry grass growing in such places. 

 In such situations the nests are formed of a mass of the surrounding 

 grass, consisting of both living blades and the dead straws floating in 

 the water. These are heaped into a conical mass, upon the apex of 

 which, resting but an inch or two above the surface of the water, the 

 eggs were placed. As would be supposed these structures were often 

 quite bulky. In one instance I collected all the eggs deposited iu a 

 small prairie sjough, and upon visiting the place about a week later, 

 found the birds had built smaller nests in shallow water, and deposited 

 a second set of eggs. These wei'e removed, and upon a third visit I 

 found many of the birds were nesting upon the masses of dead weeds 

 or upon old muskrat houses. The sets takeu from the above nests 



