SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. JO 



PLATE I 



Fi(i. I. — StroDialocystitcs ■walcolti, n. sp. A sliglitly slickcnsided specimen 

 from the upper side, X 2. 



Fig. 2. — S. walcotti, n. sp. A natural mold, X 2. Showing the centrodorsal 

 plate and the ossicles of the rim. On the right is preserved some of the 

 filling of the body cavity, which retains the imprint of the inner sides of 

 the plates of the upper surface. 



Fig. 3. — Same specimen as fig. 2, X 5- To show the pitting of the plates of 

 the lower side, and the spiracles of the plates of the upper side. 



Fig. 4. — Four impressions of the lower side of S. zvalcotti minor, n. var. 

 Natural size. 



