106 THE NATURALIST'S GUIDE. 



low, "White-bellied Martin." Abundant summer resi- 

 dent. Arrives from March 31st to April 12th; the first 

 of the Swallows in spring, also remaining the latest, de 

 parting about the middle of September. It congregates 

 upon the salt marshes during the latter part of August 

 and first of September literally by millions ; the air is so 

 completely filled with them that it is almost impossible to 

 discharge a gun without killing some. Nests in the mar- 

 tin-houses, or in holes in buildings. 1 was extremely in- 

 terested when, in company with my friend, Mr. Allen, we 

 found a nest containing six eggs, built in the primitive 

 manner, in a hole of an old blasted cedar-tree, upon the 

 Ipswich Sand-hills. The tree had probably stood there for 

 centuries. 



53. Cotyle riparia, BOIE. hank Swalhiv. Abun- 

 dant summer resident, especially along the coast. Arrives 

 from May 1 3th to 2 1 st ; leaves the last week in August. 

 Breeds by the thousand in the sandy banks along our 

 shore, also in the interior. Both sexes assist in incuba- 

 tion. 



f)4. Progne SUbis, BAIRD. Purple Martin, "Black 

 Martin." Common summer resident ; somewhat local in 

 its distribution ; very abundant upon Cape Cod, while in 

 some places in the interior it is rare. Arrives the last 

 week in April ; leaves about the last week in August. 



YIREONIIXE,- - THK VIREOS. 



55. Vireo olivaceus, VIEILL. J\e<J-eyed Vireo. Very 

 abundant summer resident. Arrives from May 4th to 

 19th ; leaves about the middle of September. Nests on 

 trees in the woods, where it is always found. 



56. Vireo gilvus, BON. Warbling Vireo. Common 

 summer resident. Arrives from May 8th to 16th; last 



