Lower Chalk Fossils. 
Fig. 18—Lima globosa, Sow, . (nat. size). 
„ 19—Lima aspera, Sow. (nat. size). 
„ 20—Stauronema Carteri, Sollas (half nat. size). 
„ 21—Stauronema Carteri (mesh magnified). 
„ 22—Serpula umbonata, Sow. (nat. size). 22a, under surface; 22/>, 
upper surface. 
