NEBULA TO MAN 
Whilst some possessed with strange adaptive powers 
Have shells that look like little twisted towers. 175 
Truly the race is straining every nerve, 
'Midst stress and change, its footing to preserve. 
And could ram-headed Ammon see them rise, 
Scarce would he here his namesakes recognise. 
Thick crowd the Belemnites in shallows still, 1 80 
But they have passed the summit of their hill, 
And now decline. From long times on the wane, 
The nautili revive, and thrive again ; 
Though they in Jura forms unchanged remain. 
Limpet and other Gastropods advance, 185 
And soon will they attain predominance 
Amongst sea-mollusk groups, as far and near 
Ammonoids and Belemnites disappear. 
Already well -developed types presage 
Great future for them in the coming age. 190 
For now 'mid earlier forms, " Fig," shells appear, 
" Helmet," and " Stair case," " Spindle," " Rice," and " Ear." 
Some early dog-whelks too are here and there. 
Innumerous oysters giant forms and small 
Gregarious live along the littoral. 
Here too pearl-mussels, it would seem, are thriving, 
For some in shells a yard in length are living. 
And Hippurites, so called, bank off the shore 
In long-drawn shells, horn-shaped and lidded o'er. 
84 
