FAMILY COLIMACEA. 99 



to its shell, its habits, and its geographical distribution. In the 

 soft parts it scarcely differs from Aehatina or Bulimus. The shell 

 is of a narrow cylindrical form, varying little in shape and dimen- 

 sions through a very considerable number of species, always convo- 

 luted sinistrally; and the aperture is more or less furnished at 

 maturity with teeth and internal thread-like plaits. Its chief pecu- 

 liarity of habit, denoted by the name of the genus, is a facxdty which 

 the animal possesses of closing itself in the shell by means of a 

 calcareous appendage, a spoon-3haped lamina, conforming to the 

 contour of the aperture, attached by an elastic filament to the colu- 

 mella. "When the animal crawls forth, the clausilium is pushed 

 aside against the columella ; when retiring into its shell, it closes 

 on the retreating animal by the aid of the elastic filament. 



The geographical distribution of the genus is altogether peculiar. 

 Nine-tenths of the Claiisilice are of the true Caucasian type, having 

 their centre of creation developed to a most prolific extent within a 

 comparatively limited area in the south-eastern parts of Europe, 

 including the islands of the Grecian Archipelago, and in Asia 

 Minor. Upwards of three hundred species have been described 

 from this locality, the greater portion of them being inhabitants of 

 Austria and Hungary ; but their progress westward is curiously 

 limited, jSTot more than a dozen well marked species inhabit 

 France, and only four of these range into Britain, one alone reach- 

 ing Ireland. In addition to the European and Western Asiatic 

 species, a few Clausilice differing very little in typical character 

 appear in wide-spread localities ; Madeira has sis of its own, Java 

 five, Burmah four, India five, China ten, Japan five, Borneo one, 

 the Philippine Islands one ; a species is recorded from Cairo, one 

 from Sennaar, and an interesting and beautiful species has been 

 collected within the present year by M. Mouhot in Cambojia. 

 There are no Clausilice in the United States, nor in any part of the 

 Western Hemisphere, excepting five in the West Indies and Cen- 

 tral America. A species has been recorded from Peru, but some 

 doubt attaches to this statement. Of the British species, one, 

 C. perversa, is universal, the others are confined to the central and 

 southern counties of England. They are : — 



1. lammata. Shell moderately large, comparatively smooth, 



semitransparent, rufous brown or straw-colour. 



2. biplicata. Shell rather larger, densely ridge-wrinkled through- 



out, dingy oHve-brown. 



h 2 



