INDEX. 
4o-> 
Rliipidoglos.^a 264, formula 2G^. 
Kibl)e(l jaw (see Odontognatha). 
liimate univalve 29. 
Rostrate jaw (see O.xygnatlia). 
Rostrum 42, d4, 186. 
Rotation of embryo 382. 
Rough waters, ettects of 79. 
Rounded, aperture 33, bivalve ul, 
l)eripbery 31. 
Routes of migration 392, pi. iii. 
Salivary glands, section 276, Cyclo- 
stonia clegans 276, Helix ti.spersr/ 153, 
H. horteusin 275. 
Sarcobelum 365, Aijrioliinax agrestis 
365, Ziiri liibrica 365. 
Scalarid univalve 26. 
Scalariform univalve 25, 26. 
Scahariformity 116, 117, causes of 117, 
artilicially produced 118. 
Sculpture 70, significance of 22, 27, 
inliuence on size 70, of Ci/rlonfoiiKi 
elrf/avs 71, embryonal shell 72. 
Secondary, period 4')G, shell 5, ureter 
336. 
Secretory (.see (Jlandular system). 
Segmented jaw (see I’olyplacognatha). 
Segmentiua nitida, aperture 35. 
Seminal vesicle 101, 3.59. 
Semper's organ 185, 190, 243, 275, in 
Agridlitnax agrrsti.s 243, Liinax 
cinerco-niger 243. 
Sensory, ganglia (see Cerebral ganglia) 
nerves (see Afferent nerves), organs 
223, cells 170, 224. 
Sei)tate ai)erture 35. 
Se.xual, dimorphism 26, 30, .353, sys- 
tem 350. 
Shallow water, efl'ects of 79. 
Shell gland 322. 
Shell, literature 131, short-spired uni- 
valve and cause of 62, significance 
of 19. 
Shells as money 431. 
“ Showers of snails ” 430. 
Sight 230. 
Simple peristome 31, 32. 
Sinistra! univalve 23. 
Sinistrorsity 2'4,10S, cause of lo9. 
Sinupallia 10. 
Sinuous aperture .34. 
Sinus, anterior 44, posterior 44. 
Sii>honal, margin 30, retraetois, Atw- 
donfa 181, tubes 199, 200. 
Size, correlation with temper.ature 80, 
effect of altitude on 85, crowding 
of darkness 85, of environment 8o, 
marine influence 85, water volume 
80, 82. 
Skiojitic vision 235. 
Somatic muscles I4I. 
Sonant organs 242. 
Specific names, formation of 10. 
Species, defined 50. 
Sj)eed, of gastropods 348, Cyclodoma 
349, basommatophor.a 349, AnegJua 
fl a eiatilis 349, Dreissensia 350, Helix 
aspeesa 34.9, H. cetntiona 349, Limax 
34s, Limneva peregra 349, Felecy- 
poda 349, Planorbi.'i corncus 349, 
Uirio viorgaritifce 350. 
Spengel’s organ (see Osphradium). 
Sperm duct 360, of Helix 160, 101. 
Spermatheca e>iH. n.-iper.sa \^Q,102,35S. 
Spermatophore, of Helix aspersa 161, 
of H. virgafa 376, of Amalia soirer- 
bgi in epiphallus as secreted 376, in 
spermatheca as transferred in pair- 
ing 376, rival sperniatophores in 
spermatheca 374. 
Spermatozoa I4I, of Heli.r 100, 374, 
development 375, dimorphic 375. 
Splavrium eorneiim 4I, development 
290, hinge teeth 47, 53, periostracal 
hairs 49, 70, 201, otolitli 241, otolith 
and sensory hairs 238, siphonal tubes 
200 . 
V. 7nicleii.'i 53, 191, v. vittata 51. 
Sp/urriiim lacu.stre, caliculation 43, 
form 52. 
Spha-i'iiim pallidiem 41, form 51. 
Sjdta’i'ium, I'ieicola form 40, 51, hinge 
teeth 47, sub-reptatory foot 195. 
Spiculum amoris 366. 
Spinose sculpture 27. 
Spiral ojierculum 1.25, 126. 
Spiral white lineation 102, causes of 102 
Spiral striation 27. 
S|)ire, defined 30. 
Splanchnic muscles I4I. 
Spleen (see Lymi)hatic gland). 
Spoons, Roman 424. 
Staining of buccal armature 273. 
Stenodontophora 266. 
Stiebel’s canals (see Pronephros). 
Stomodicum 185, 247. 
Stomato-gastric gangli.a 1.37. 
Stomach, 245, 277, Anodemta 171, 172, 
Cgclo.stoma elegaiis 277, Helix as- 
pci-.m 153, cells of, in H. pomatia 
277 , section of w.alls of, in Helix 
pomatia 277. 
Strength of snails 3.50. 
Streptoneura, 0, anterior pedal gland 
190, huccal bulb section 248, buccal 
muscles 247, epipodial lobes 193, 
nephridia 334, 536, nervous system 
213, odontophoi al classification 204, 
operculigerous lobe 193, organiza- 
tion of 143, perie.ardial gland 338, 
pronephros 337, retractors 343, teeth 
of 264, 265, tor.sion of nerves 220, 22 1 . 
Striated jaw (see Pycnognatha). 
Striation 27, spiral 27, transverse 27. 
Structural defences of plants 287. 
Structure of shells ,2i, bivalve 21, 37, 
univalve 20. 
