2^2 



CLASSIFICATION OF ANIMALS 



vr 



< ^ I / ' 



db. 



r.n. 



Fig. 142. — Section through the arm and disc of a starfish. A, Anus; amp, 

 ampulla; cb, circular blood-vessel; cw, circular water canal; co, coelom; co.e., 

 coelomic epithchum; d.b., dermal branchiae; e, eye-spot; cct, ectoderm; ent, ento- 

 derm; /, ambulacral foot; g, ambulacral groove; h, hepatic caeca; i, intestine; 

 i.e., intestinal caeca; mcs, mesoderm; wo, mouth; mp, madreporic body; nr, 

 ner\'e ring; os, ossicles; rn, radial nerve; rb, radial blood-vessel; rp, genital pore; 

 rw, radial water canal; sc, stone canal; sp, spine. (From Galloway.) 



Fig. 143. — Cross section of the arm of a starfish, ar, Ambulacral rafter; ov, 

 ovary containing ova. Other lettering as in preceding figure. (From 

 Galloway. ) 



