ANATOMY AND PHYSIOLOGY. 
Moll. 13 
Zool. xxxi. pp. 482-484. M. Braun, Zool. Gart. xix. 1878, pp. 161-170 ; 
also JB. mal. Ges. v. pp. 307-319, and Zool. Anz. i. pp. 7-9 ; abstract in 
Verb. Ges. Wiirzb., May, 1878. 
Observations on the development of Purpura lapillus by Robin, M^m. 
Ac. Sci. xl. [1876] No. 9, pp. 72, 141, 273-278, 298, 316-322, pis. xvii. & 
xviii. ; of Limncea and Ancylus fluviatilis, tom. cit. pp. 64, 65-79, 141, 
273-278, 344-369, pi. xix. 
Eggs of Limncea stagnalis (L.), hatch in 17 days in violet light, in 19 
in blue, 25 in yellow, 27 in white, 36 in red light, 33 in darkness. E. 
Yung, Arch. Z. exp^r. vii. pp. 273 & 274. 
The calcareous eggs of BuUmus are distinct from those of birds and 
reptiles in their vitreous transparent surface, which is either entirely 
smooth or only slightly roughened at the extremities by flat granules and 
sharply defined pores. Konig-Warthausen, Mal. Bl. xxv. pp. 176-178. 
7. Biology. 
G. S. Tye gives some very interesting observations on the spinning of 
several Molluscay chiefly Limnceidce, but also slugs and P ectinihranchia^ 
partly from his own observation, with special regard to Warington’s paper 
on the same subject in the “Zoologist,” 1852. Q. J. Conch. 1878, No. 17, 
pp. 401-415. 
Limax agrestis spinning slimy threads, T. Eimer, Zool. Anz. i. p. 123 ; 
a short account of similar observations by several previous authors, from 
Lister (1678) to Harte (1865), on different species of Limax^ on Megaloma- 
stoma suspensum (Guildiug), on Potamides obtusus, Physa^ Valvata^ and 
Pissoa, by the Recorder, tom. cit. pp. 249-251. 
Natica perforating other shells; Leidy, P. Ac. Philad. 1878, p. 332. 
Patella abrading the surface of rocks, observed by J. Clarke Hawk- 
SHAW, J. L. S. xiv. pp. 406-411 [infra]. 
Notes on birds as enemies of bivalve Mollusks, by W. A. Durnford, 
Zool. 1878, pp. 223-225. 
8. Abnormities. 
S. Clessin discusses some of Leydig’s [Zool. Rec. xiii. Moll. p. 6] 
observations upon the differences of the cuticle in several land- shells, 
and remarks that the development of this part, which gives the surface 
sculpture to many shells, depends on the supply of fresh vegetable food, 
and that where snails live in layers of decayed leaves their shell becomes 
unusually thin, because they have no access to calcareous substances. 
Mal. Bl. xxv. pp. 143-148. 
A Ihino varieties. V. Gredler enumerates a rather large number iu vari- 
ous Alpine species of Hyalina., H-elix, Bulimus, Pupa, and Clausilia ; he 
inclines to think them hereditary, but acknowledges that they are some- 
what morbid, the albino being often smaller than the coloured specimens, 
and found chiefly near the vertical or horizontal boundary of distribution 
of their species. Nachr. mal. Ges. 1878, pp. 33-37. Some other instances 
of albinism in land-shells mentioned by Oberdorfer, tom. cit. p. 69. 
P. Hesse has observed some instances of albinism on Mt. Wittekind, 
