The Collaborative International Dictionary of English v.0.48:

Heterosomati \Het`e*ro*so"ma*ti\, n. pl. [NL., fr. Gr. ? other +
   ?, ?, body.] (Zool.)
   An order of fishes, comprising the flounders, halibut, sole,
   etc., having the body and head asymmetrical, with both eyes
   on one side. Called also Heterosomata, Heterosomi.
   Heterosporic