W. KEEPING ON THE DISCOYEEY OF MELONITES IN BETTAIN. 



397 



Figs. 1-6. — Melonites Etheridgii, sp. n., from the Carboniferous 

 Limestone of Derbyshire. 



Fig. 1. 

 Fig.6. 



Fig. 4. 



Fig. 3. 



Fig. 2. 



Fig. 5. 



Fig. 1. Crushed specimen of Melonites Etheridgii, n. sp., half nat. size (Museum 



of Practical Geology). 

 Fig. 2. The ambulacra! mass marked x * n %• 1« The outer festooned border 



and the spines are shown. 

 Fig. 3. An interarabulacral plate, showing the bevelled edge and the tubercles. 

 Fig. 4. One of the marginal interambulacral plates, showing the grooves for 



the articulation of the ambulacral plates. 

 Fig. 5. Tubercles, magnified. N.B. The rings around the tubercles are here 



made to look too angular and too prominent. 

 Fig. 6. Spine, much magnified. 



