The Collaborative International Dictionary of English v.0.48:

Phyllosoma \Phyl`lo*so"ma\ (f[i^]l`l[-o]*s[=o]"m[.a]), n. [NL.
   See Phyllo-, and -some body.] (Zool.)
   The larva of the spiny lobsters (Palinurus and allied
   genera). Its body is remarkably thin, flat, and transparent;
   the legs are very long. Called also glass-crab, and
   glass-shrimp.
   [1913 Webster]