An "x" is generally not a great thing. This means that something was wrong (the anterior border of the epiploic foramen is the gastroduodenal ligament -- wrong: big red x here). X's are not thrown about lightly. If you see and X with a bunch of horizontal lines through it that means that I originally thought something was incorrectly written and later realized that it was incorrectly read.
A cross with a circle is not a great thing. Sometimes the circle is not directly centered over the cross. Generally, a cross with a circle means that, in light of the current discourse, I expected (hoped) that certain additional information would be given at that point in the answer. Thus, a plus with a circle refers to an omission. Possibly, the "omitted" information appears later in the answer. Generally, if this is the case, I go back and put a series of horizontal lines through the circled cross.
Often times, there are circled crosses over the prompts provided by the wording of the question. For example, a circled cross over the word "lymphatics" means that something about lymphatics was omitted from the answer. Almost everyone received a cross over the word "anatomy" on the question about the pericardium. This is because only about 4-5 people mentioned the oblique and transverse sinuses.
I was impressed with the answers to the essay questions. The highest score for the 3 questions was 33. This was for one or two exams. A score of 24 was about the norm. This is not a bad score. You knew an amazing amount of the material. Scores above 28 were relatively rare. Scores below 22 are cause for some concern. In some cases, low scores were simply the unfortunate result of not absorbing the question. A few people's expectancies got the best of them and they wrote about a question that was not asked. There was a great answer that pertained to the anterior thigh rather than the anterior leg.
You stay classy, Planet Earth.