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. — Banh 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 ; 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. 
VIEEONIDiE, — The Vireos. 
55. Vireo olivaceus, NmYUL.—Ped-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 
