EXPLANATION OF PLATE XXXI. 



Figure 233. — Creuelia glandula, (p. 695.) 

 234.— Mytilus edulis, (p. 692.) 

 235. — Modiolaria corrngata, (p. 694.) 

 236. — Modiolaria nigra, (p. 694.) 

 237.— Modiola modiolus, (p. 693.) 

 238.— Modiola plica-tula, (p. 693.) 



(All the figures are of natural size, and from Binney"s Gould, drawn by E. S. Morse.) 



