Backyard and Beyond

The rain in the middle of the week bought the snails out in the Back 40. Half a dozen were visible from the door for the rest of the week. All are the big ones, Cepaea nemoralis, an introduced species. I’m sure there are others. These two were getting frisky.

More snails: the surprising abundance of snail species in my concrete backyard was one of the inspirations for this blog five years ago. I will be moving in May, to a deluxe apartment in the sky… well, the 4th floor, anyway, of a walk-up, in Sunset Park, and not deluxe by the plutocratic democracy-squelching standards of our second Gilded Age, but… …home is where the shell is.

Slicking up the back door. Faster than you think.

I like the idea of one gastropod hanging out in the shell of another. You’ve seen this before: the Queen Conch shells I lugged home — not from the Caribbean, but from Dead Horse Bay’s eroding landfill — provide an excellent shelter for terrestrial snails. Cepaea nemoralis, the Brown-lipped snail. A new squatter, as an individual, but a familiar species.

Responding to my last post, snail maven Aydin Örstan thought the third of the terrestrial snails harboring on the marine snail shell in my backyard was Vallonia costata. If so — and it looks like it to this mollusk amateur — that would make for five different species of snails found in my concrete slab of a Brooklyn backyard so far.

This snail is tiny, 2mm across, and posed here on FDR’s eye on a dime. My antique snail book, Shells from Cape Cod to Cape May with Special Reference to the New York City Area (Dover, 1971, reprinting a 1961 original) by Jacobson and Emerson, notes that this Eurasian species wasn’t reported in the NYC area until “recently” when some were found in the Bronx, in a colony subsequently destroyed by construction. Jacobson and Emerson inform me that the ridge-like axial ribs on this shell are also known as costae.The hollow at the center of the whorl is called an umbilicus.