Source : Webster's Revised Unabridged Dictionary (1913)

Chelonia \Che*lo"ni*a\ (k[-e]*l[=o]"n[i^]*[.a]), n. pl. [NL.,
   fr. Gr. chelw`nh a tortoise.] (Zo["o]l.)
   An order of reptiles, including the tortoises and turtles,
   peculiar in having a part of the vertebr[ae], ribs, and
   sternum united with the dermal plates so as to form a firm
   shell. The jaws are covered by a horny beak. See {Reptilia};
   also, Illust. in Appendix.

Source : WordNet®

Chelonia
     n 1: green turtles [syn: {genus Chelonia}]
     2: tortoises and turtles [syn: {order Chelonia}, {Testudinata},
         {order Testudinata}, {Testudines}, {order Testudines}]