We have conducted an extensive survey of the Magellan data to reassess the population of coronae. We identify a new type of coronae, here referred to as 'Type 2 coronae', having the same basic morphology as previously identified coronae (Type 1), but lacking a significant (>50%) annulus of closely spaced fractures. 106 Type 2 coronae are included in the new database giving a total of 515 coronae on Venus. The characteristics of the expanded population of Type 1 coronae are similar to those of the previously described population, but the Type 2 coronae are smaller, tend to have relatively flat interiors surrounded by a topographic rim, and are more likely to be found isolated from other features. Our observations, in particular the morphology and setting of the Type 2 coronae, may provide supporting evidence for the existence of a depleted mantle layer under the venusian plains. ¿ 2001 American Geophysical Union