Origin of pleon
Examples from the Web for pleon
Telson, tel′son, n. the last somite of the pleon or abdomen of certain crustaceans and arachnidans.
This tribe has the pleon dwindled into insignificance, whereas in the other two tribes it is powerfully developed.
The abdomen or pleon carries the remaining six pairs, of which from three to five are called pleopods and the remainder uropods.