Layer Estimates:

Layer: Boston 311 Complaints (ID:0)
Count: 276723
Extent:

XMin: -7924322.47991549
YMin: 5195524.90417407
XMax: -7903116.11691938
YMax: 5220363.55522467
Spatial Reference: 102100 (3857)

Layer: TRACTDENSITY (ID:1)
Count: 1613
Extent:

XMin: -8185691.67528445
YMin: 5046537.84067292
XMax: -7781072.91798247
YMax: 5294988.4831007
Spatial Reference: 102100 (3857)

Layer: census_tract_data_csv (ID:2)
Count: 207