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. I 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. Bank Swallow. Abun- 

 dant summer resident, especially along the coast. Arrives 

 from May 13th to 21st ; 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. 



54. Progne SUbis, BAIRD. Purple Martin, "Black 

 Martin." Common summer resident ; somewhat local in 

 its distribution ; yery 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. 



VIREONID.E, - THE VIREOS. 



55. Vireo olivaceus, VIEILL. Red-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. - - WarUing Vireo. Common 

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



