ANA.TOMY AND PHYSIOLOGY. 
Moll. 19 
weight, or 20 per cent, of the water they contain ; snails with a shell lose 
by evaporation much more slowly than naked slugs ; both, after having 
been exposed to dryness for some time, eagerly take water also by the 
mouth. Beitr;ige, &c., pp. 17-42. 
Experiments on the absorption of water in Helix ^'po'ma,tia have also 
been made by Mer, The water is absorbed not only by the skin, but 
also by the walls of the pulmonary sac and the digestive tube. If im- 
mersed in water the experiment may be continued for three days ; the 
quantity of absorbed water exceeds the snail itself in weight ; it is very 
rapid at first, but continually decreases, though without altogether ceas- 
ing, until the moment of death. CR. Soc. Biol. 1877 (1879), p. 18G ; 
abstract, J, R. Micr. Soc. ii. p. 856. 
WiEDERSHEiM has observed that 13 specimens of Limncea auricularia 
remained alive for more than two months in fresh moss, wet, but not sur- 
rounded by water ; Zool. Anz. ii. p. 573. 
On vital tenacity of Succinea pntris (L.) ; T. Gough, Zool. (3) iii. p. 62. 
Helix aspersa lived nearly a year in a closed flower-pot ; J. Ward, 
Nature, xx. p, 363. 
Tenacity of life in Litorina muricata (L.) ; Hassler, P. Ac. Philad. 1873, 
p. 284. 
J. Carriere describes mode of regeneration of the tentacles and eyes 
in Helix, and states that if the supra-pharyngeal ganglion is ruptured, no 
regeneration occurs, but the animal dies [this has also been observed by 
Spallanzani, 1769, and more distinctly stated by Schweigger, 1820. Tage- 
blatb d. 52 Versaral. d. deutschen Naturf. pp. 225 & 226. 
Cave-fauna. See in the special part, Hydrohia quemtedti^ Hyalina 
raddii. 
Depth of lakes. See in the special part, Pisidium abditum. 
12. Abnormities. 
A double monstrosity in the embryo of Philine aperta (L.) described 
by Lacaze Duthiers, Arch. Z. exp^r. iv. [1875] pp. 482-492, pi. xv. 
Sinistral specimens of Vitrina pellueida, Brot, Proc. verb. Soc. mah 
Belg. vi. [1877] p. xlvii. Of Hyalina nitidula (Drap.) ; Gredler, Nachr. 
mal. Ges. 1879, p. 107. Of Zonites nitidus', Gassies, Bull. Soc. Bord. 1878. 
Of [^Azeca~\ Cochlicopa tridens\ Taylor, J. of Conch, ii. p. 221. 
Scalarid monstrosity of Helix aspersa ; J. de Guerne, Bull. Sci. Nord, 
(2) ii. pp. 321 & 322. Of Clausilia nigricans and biplicata, Limncea stag- 
nalis, Planorbis albus, rotundatus, and Bithynia tentaculata ; Hesse, JB. 
zool. sect. Westf. Mus. 1879, pp. 95 & 96, pi. ii. figs. 1-4. 
Abnormity of Paryphanta liochstetteri (Pfr.), total absence of calcareous 
deposit in the shell; E. A. Smith, Zool. (3) ii. [1878] p. 61. 
Albino varieties of Limax variegatus ; Fries, Zool. Anz. ii. p. 155. 
Helix rotundata, several specimens, and if. hispida ; J. Butterell & H. 
Pollard, Naturalist, iv. [1878] pp. 25 & 170, Taylor, J. of Conch, ii. 
p. 282, and Hesse, JB. zool. sect. Westf. Mus. 1879, p. 95. Helix alternata, 
palliata, multilineata, s^ndprofunda, in Michigan ; Walker, J. of Conch, 
ii. pp. 328 & 329. Cionella lubrica in Silesia ; Jordan, JB. mal. Ges. vi. 
