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Page:Popular Science Monthly Volume 56.djvu/488

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474
POPULAR SCIENCE MONTHLY.

themselves in Wyandotte Cave, where they bring forth and rear their young. They have exterminated the cave rats, and now station themselves in a narrow passage of the cave and capture bats as they fly through.

Among the permanent residents in dark places we have, among mammals, the moles, which habitually live in burrows of their own make. In—Mammoth Cave lives a rat— PSM V56 D0488 Cave salamander of the mississippi valley.pngFig. 1.—The cave salamander of the Mississippi Valley (Spelerpes maculicauda). Neotoma pennsylvanica. In Marengo Cave, Indiana, white-footed mice have established themselves. Although with unimpaired eyes, they have acquired ears and whiskers longer than the rest of their kind living outside.

In Florida occurs a blind lizard—Rhineura floridana. It burrows in the ground, and is colorless and blind.

Of salamanders, one blind species lives in European caves. In the large caves of the eastern United States no blind salamanders have been found, although other species, especially Spelerpes maculicauda, abound. In the caves of Missouri a veiled eyed salamander, Typhlotriton, has been described within recent years by Stejneger. Still another salamander, Typhlomolge, having rudimentary eyes, has been cast up from an artesian well at San Marcos, Texas, and occurs in the cave streams about that place.

The most abundant of the blind vertebrates, both in individuals and in species, are the blind fishes. These, from their geographical distribution, may be separated into three groups: (1) Those inhabiting the depths of the ocean; (2) those inhabiting dark places along the shores of the ocean; (3) those inhabiting the underground fresh waters.

The fishes, blind or partially blind, living in the depths of the ocean bordering the American continents, are as follows: 1. Ipnops Murrayi Günther lives at depths varying from 955 fathoms to 2,158 and has the very wide distribution suggested by the localities from which specimens have been secured—viz., off the coast of Brazil, near Tristan da Cunha, near Celebes, latitude 24° 36' north, longitude 84° 51' west, and off Bequia. This is the only vertebrate in which no vestige of an eye has been found. Ipnops stands alone in a family. 2. The Brotulidæ have several members blind or with very much reduced eyes in various parts of the globe.