Cornuspiridae

Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

This is the older part of the test. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

The successive whorls of the test do not expand nearly as much in this species as they do in other members of the genus. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

As this foram grows, the broad edge of the younger parts of the test may begin to branch away from each other. Here, the process is beginning with the formation of distinct lobes. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

This example of the species has completely abandoned the typical coiling pattern and is growing in a rectilinear, branching pattern. The younger part of the test is to the left. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

This species is often found in Explorers Cove, a relatively quiet and undisturbed area on the coast of the Ross Sea. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

Notice the prominent ridge along the outside of the coil, which gives this species its name. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

Notice the dramatic change in shape as the cell grows. The young foram produces a tightly coiled test (the whorl at lower right), but later growth spreads out n a disc-like shape. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

This young foram is just bginning the change in growth pattern that is much more distinctive in the adult. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

This species is found in several places in the North Atlantic and the Arctic Sea. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

Notice the interior architecture of the test: a slightly ridged but undivided tube. Image courtesy of Gudmundur Gudmundsson, Icelandic Institute and Museum of Natural History. This image was originally published in J. Foram. Res. 32:308-318, and is used with permission.

Cornuspira planorbis.