PLATE XX. 



\u.. . Jj,,:ale aceratn Kirkj. JJ „.t. .izc, p. 3C ; a, surface ( x 5) ; ^ vertical section, „at. size. 

 Hg. > 3rycale ,nageMan,m (RKlley). Dermal reticulum showing the uniformly level surface p 3(i 

 Fio. :.. E.penops,x villom (Carter). Nat. size. p. 35 ; a, h, villous and pOose surface ( x ]()) . vertical 

 section ( X 5). ' ^ j^ i •viuiv-a. 



K'... 4. ^ ^;^,./.^«« ,,p„,iM, (R. & o.). g nat. size, p. 34 ; a, villous process on the surface of the sponge 

 (X :0 : I), surface (X 5) ; c, vertical section (X 5). 



