This genus resembles Limax in its shield-like mantle, but in the more essential characters of the lingual teeth, appears to belong undoubtedly to the Helicidæ. It approaches nearest to the subfamily Vitrininæ, in having the mantle in front of the shell, approaching nearest to the Daudebardia of Europe; but differs in the form and opacity of the shell, which resembles some of the Succininæ, especially Omalonyx of South America, etc. It differs from these very much in the form of the animal, and the shell being wholly external, forming one of those connecting links which make it difficult or impossible to divide the Helicidæ into distinct groups.
Habitat. So far this animal has been found only in Santa Barbara Island, one of the group within this State. It there inhabits but one station, so far as I could discover after very careful search. That is the head of a ravine facing the south-east and about two hundred and fifty feet above the sea. During the wet season there may be a little water springing from this place, but for at least five months it is not even damp, while the remainder of the island is entirely destitute of water. Myriads of Helix kelletii and two other species (probably new) inhabit it, but during the dry season retire into a torpid æstivation, not disturbed by the fogs and mists of summer. The Binneya, the rarest of all, and not protected from drought by its shell, burrows down to the under surface of thick succulent roots, and contracting to about twice the size of its shell, covers the rest of its body with a white mucous secretion, which appears to be impervious to the moisture within, and dries into a tough leathery shell.[5] When moistened for a few hours, the animal separates the edge of this box from that of its true shell, and becomes active.
The figures [[Fig. 15]] represent three positions of the shell, the animal æstivating and also crawling.
Fig. 15.
I found but three alive, and eighteen dead shells.
[4] To all those who have seen the splendid works on the “Terrestrial Mollusks of the United States,” by the late Dr. Amos Binney, so ably continued by his son W. G. Binney, the appropriateness of the name will be at once evident.
[5] In this it resembles the Testacellæ of Europe, which are otherwise very different.
Dr. Trask presented, in the name of Mr. Garrett, the following paper: