People found there were only existing 15 types of pentagonal tiling after one hundred years' work, see [Pentagonal tiling](https://en.wikipedia.org/wiki/Pentagonal_tiling#cite_note-FOOTNOTESchattschneider1978-8).


These 15 types of pentagonal was named by finding date except type 9 and type 10:


type 10 pentagonal was found by James in 1975,
type 9 (also type 11, type 12, type 13) pentagonal was found by Rice in 1976.


I cannot understand: why not named pentgonal found by James as type 9?



Order question about pentagonal tiling type 9 and type 10
The "numbers" of types 9 up to 13 were probably fixed by Doris Schattschneider "Tiling the plane with congruent pentagons" (1978). She tried to explain the possible cause(s) for the omissions of Kershner: in types 1 up to 8, each tile either edge-to-edge, and/or each tile is adjacent to at most 6 other tiles. But either with the two conditions of edge-to-edge and with at most 6 neighbors, there is one omission: the type 9. It's maybe why she gives the number 9 to that tiling. <https://en.wikipedia.org/wiki/Talk:Pentagonal_tiling#/media/File:15_pentagonal_tiling_colored_by_edge-to-edge_sides.png>


