I'm looking at the Arduino megapololu shield schematic, and up in the left hand top corner are the pins for Arduino connectors. I am familiar (was?) with the pins of the Arduino boards, and have used the boards several times. This shield schematic has only the 'local' signal names, with no match to the Arduino pin (signal/port) names. The two vertical rows suggest the sockets on the sides of the Arduino, but neglect the sockets on the end. A0-15 and D0-53 simply don't match! I've pulled up Arduino pinout drawings, the MegaPinOut is quite complete and useful.
What is the correlation between the RAMPS board names and the Arduino names? What am I missing? For example, if I want to control heaters and fans; D8, D9 & D10 are what Arduino Mega chip pins?