PLATE IV. 



Fig. 



1. Necrocarcinus Woodwardii (p. 20), from a fine specimen in Mr. Norman's collection, 



from " the Chalk Marl, capping the firestone," at St. Lawrence, m the Isle of 

 Wight. 



2, 3. Small specimens of the same, from the Greensand of Wiltshire. In the collection 



of Mr. Cunnington. 

 4 — B. Necrocarcinus Bechci (p. 20), after specimens in the collections of Dr. Bowerbank 



and the author, from the Gault, at Folkestone, and the Greensand of Cambridge. 

 9. Necrocarcinus tricarinatus (p. 21), from Wiltshire. In Mr. Cunnington's collection. 

 10, 11. Smaller specimens of the same, from Cambridge. In the author's collection. 



