GASTROPODA (pDLMONATA). 
Moll, 81 
These two groups are connected by P. trivolvis (Say). Periodical swellings 
of the whorls are seen conspicuously in P. glabratus (Say), and lumens 
(Carp.), eccentric coiling in P. plexatus (lugersoll), both occur also 
more or loss distinctly in all of the larger American species, and are 
probably caused by the influence of recurring seasons of hibernation and 
activity. West of the Rocky Mountains, the average size of the shells 
of this genus is larger, and the variations referred to are more con- 
spicuous. ,P. Ac. Philad. 1881, pp. 92-108, with 24 woodcuts. 
Planorhis metatar sius, sp. n., prceclarus (Letourneux, MS.), both be- 
longing to the group of P. corneiis, from Lake Balaton, with a list of 
16 pretended European species of the same group, and note on P. almis- 
sanus (Letourneux, 1878) ; Servain, Hist. mal. Balaton, pp. 79-84. 
Planorhis marginatus (Dr.) var. n. fontinalis^ and P. spirorbis (Miill.) 
var. n. hazayanus (Clessin), Buda-Pest, Hazay, Mal. Bl. (2) iii. 
pp. 169-173, — var. subangulata (Phil.) and var. sieversi (Mouss.), 
Armenia, Bottger, JB. mal. Ces. viii. pp. 252-354 ; P. umbilicatus (Miill.) 
[= marginatus'] var. n. armeniacus, Armenia, Westerlund, QGfv. Ak. 
Forh. 1881, p. 62. 
Planorhis rotundatus (Poiret) var. n. angulatus ; Milachevich, Moll. 
Mosc. p. 25, Government of Moscow. 
Planorhis vorticulus (Troschel). Note on it by Westerlund, JB. mal. 
Ges. viii. pp. 1 & 2. 
Planorhis (^Gyraulus) socius and concinnus, Sweden, stroemi, Norway, 
Finland and Siberia, and tetragyrus, Dalmatia, spp. nn., and list of 26 [!J 
European species of this subgenus; Westerlund, (Efv. Ak. Forh. 1881, 
pp. 62-65. 
Planorhis complanatus (L.) var. n. hohelti, Hazay, Mal. Bl. (2) iii. 
p. 180, and Westerlund, 1. c. p. 65, Buda-Pest, also Troyes, in France. 
Planorhis rollandi^ sp. n., Morlet, J. de Couch, xxix. pp. 46 & 344 
[1882] pi. xii. fig. 4, Algerian Sahara, subfossil. 
Segmentma servaini (Bourguignat, MS.), Hungary and Croatia, clessini 
(Westerlund), Northern Europe, microcephala (Charp., MS.), France, 
and montgazoniana (Bourguignat, sp. n.). Depart. Aube ; Servain, Hist, 
mal. Balaton, pp. 86-90. 
Segmentina (Planorhula) alencandrina (Ehreub.) var. n. tanganyicensis, 
E. A. Smith, P. Z. S. 1881, p. 294, pi. xxxiv. fig. 30, Lake Tanganyika. 
Segmentina (^Planorhulo') newcomhi^ sp. n., Ancey, Le Nat. iii. p. 468, 
Bahamas. 
Carinifex. Variability in shape of the shell and list of known locali- 
ties ; Stearns, P. Ac. Philad. 1881, pp. 108-110. 
Ancylus lacustris (L.), floating ; Pearce, Sci, Goss. 1879, p. 207 ; 
J. of Conch, iii. p. 185. 
Ancylus fluviatilis (Miill.) var. n. armenia\ Bottger, JB. mal. Ges. viii. 
p. 265, pl.ix. fig. 21, and Nachr. mal. Ges. 1881, p. 128, Erivan. 
Ancylus expansilahris, Middle Europe, and subcircularis, Bohemia, 
spp. nn., Clessin, Mal. Bl. (2) iii. p. 159. 
Ancylus tinei (Bourg.) distinct from hcnoitianus (Bourg.), Paulucci, 
Bulk Soc. mal. Ital. vii. p. 144. 
Ancylus striatidus, sp. n.,Phthiotis, ellipticus, sp. u., Thebes and Euboea, 
