TESTACELLA. 29 



of its own. It is a ground slug of strictly carnivorous habits, pene- 

 trating the soil to the depth of two to three feet, or more, and 

 preying voraciously upon earthworms. There is, moreover, as 

 already noticed, no shield in Testacella, although in Vitrina a modi- 

 fication of the Limax shield appears along with a more advanced 

 convolution of the shell. 



It was stated by De Ferussac that the mantle of Testacella 

 though ordinarily concealed beneath the shell, is susceptible of be- 

 ing extended over the whole body of the animal. " When the 

 Testacellce are surprised by drought, they envelope themselves 

 entirely with their mantle. The mantle, which is extremely gela- 

 tinous, preserves the animal in the dry soil in a state of freshness 

 and humidity, which appears indispensable for it to live. The body is, 

 it is true, contracted, but it augments in thickness although it di- 

 minishes in length." This statement is regarded with incredulity 

 by Moquin-Tandon, but Mr. Woodward has given a wood-en- 

 graving of this singular phenomenon as observed by Mr. Cunnington 

 in a field near Devizes, in a supplementary note to his ' Manual of 

 the Mollusca,' accompanied by the following interesting description : 

 — " During winter and dry weather the Testacella forms a sort 

 of cocoon in the ground by the exudation of its mucus. If this cell 

 is broken, the animal may be seen completely shrouded in its thin 

 opaque white mantle, which rapidly contracts until it extends but 

 a little way beyond the margin of the shell." There is, however, 

 reason to believe that this thin white cocoon is not an extension 

 of the mantle, but a pellicle of slimy mucus. Another phenomenon 

 in the structure of the mantle may be seen in our figure of T. Maugei, 

 engraved from a drawing by the Rev. M. J. Berkeley, in which it 

 is lobed externally on either side for the lateral embrace of the shell. 



Testacella is recorded from the West Indies, at G-uadaloupe and 

 Martinique, but we have not been able to procure specimens of T. 

 Antillarum and Matheronii to test their specific value. The genus 

 is not known in the United States or in any other part of America. 

 The shell occurs in a fossil state in the lacustrine deposits of the 

 South of France, chiefly in the vicinity of Montpellier. 



The Testacellce produce calcareous eggs of large size, as symmetri- 

 cally formed as those of a bird. A specimen before me at this 

 moment, from the collection of Mr. Cuming, was taken by him from 

 the living animal while in the act of ejecting it from the ovary. 



The species are : — 



