AM and PM lines meet near inner margin. Brown basal shade, and black border of HW usually not broken.
Nova Scotia to North Carolina, west to Manitoba, South Dakota, and Kentucky.
It appears there may not be any current diagnostic criteria for reliably and consistently separating blandula/mira/crataegi and maybe even pretiosa.
As an example, here are the *expected* appearance and differences between blandula, mira and crataegi respectively, as the written descriptions would place them:
(images courtesy of MPG, copyright Jim Vargo)
C. blandula                            C. mira                             C. crataegi
Now, here are three different images (all courtesy of BOLD Systems) of each of those species, showing the variation that will often preclude any reliable distinction based on the accepted descriptions.
It seems C. pretiosa may be more likely to be distinguished in many cases due to it's strongly contrasting pale median area, but even specimens of that species can often blend right in with the others, such as the two specimens below:
Since these species share range, food, and season, the best approach to identifying and placing them here on BugGuide (where dissection and/or DNA sequencing has not been done) is probably a combined species complex page (i.e., a blandula-mira-crataegi species page). Until that is decided and created, individual specimens are likely to be placed to the page of whichever species they most "look like" per the old descriptions.