INDEX. 
443 
Columella 29, absorption of ^9, lip 3£, 
truncation 30. 
Columellar lobule £01. 
Coluinellar muscle, in gastropod 34£, 
in Helix 159, scar of 54. 
Colmnnce cariue 291. 
Combination shells 121, 122. 
Compressed, bivalves 52, causes of 63, 
aperture 33. 
Commissures 209, 211. 
Concentric, markings in bivalves 51, 
operculum 126. 
Conchal gland (see Shell gland). 
Conchifera, defined 19. 
Conchology, defined 3. 
Conchyolin 21. 
Concretionary gland 338, concretion of 
338, function 338, bacilli of 339. 
Connate bivalves 41. 
Connectives 148, cerebro-pleural and 
pleuro-pedal 160, 209, section of 21 1. 
Connective tissue 136. 
Conoid univalves 25, 61. 
Constrictor muscles, pallial 158, pneu- 
mostome 158. 
Contabulate univalve 24. 
Continuous peristome 31. 
Contracted aperture 31. 
Coralline crag 414- 
Coronal glands 370. 
Coronate univalve 27. 
Corselet 44. 
Cordate bivalves 53. 
Costate sculpture 27. 
Crests of bivalve shell, anterior and 
posterior 43, ventral 38, 49. 
Cretaceous, fossils 409, strata 4O8. 
Crop 153, 274 
Crowding, effects of 85. 
Crystalline style 755, 245, 282, of A )io- 
donta 172, 278, of Donnx 278. 
Ciyptophallia 352, 353, gynogaina 357, 
haplogama 356, stylogama 357. 
Ctenidium 301, chitinous framework 
of 137, of Viviimra 8, diotocardiate 
pelecypod 302, monotocardiate 
gastropod 302. 
Cutaneous, respiration 306, cells 135. 
Cylostoma elegans, auditory hair cells 
238, buccal retractors 247, cleft foot 
194, cephalic region 188, concre- 
tionary gland 338, concretion 338, 
dialyneury 222, gustatory cells 242, 
locomotion 349, mandibular mus- 
cles 249, mandibles 251, muzzle 
retractors 259, nervous system 214, 
222, olfactory cells 226, operculum 
126, optic cellules 232, otolith 240, 
pallial section 304, peristome 31, 
retractors 259, rhinophore 226, ros- 
trum 186, salivary glands 276, sculp- 
ture of shell 28, 71, sexual organs 
352, sexual dimorpliism 26, speed 
349, spermatozoa, and development 
of 375, stomach, interior of 277, 
supra-pedal gland 196, ventral, 315. 
v. albescens 03. 
Cylindrical univalves 24. 
Dart (see Gypsobelum). 
Dart sac (see Stylophore). 
Darkness, effect of 85. 
Decollation 30. 
Decorative shells 431. 
Decussate sculpture 28. 
Defensive devices of j)lants 286. 
Deflected aperture 34. 
Dentate apertui e 34. 
Depressed univalves 25, 30, 61, 62. 
Depressor muscles 250. 
Dermal cells. Helix immatia 314. 
Dermatoptic vision 138, 171, 234. 
Detached peristome 31. 
Development, heart 290, 292, radula 258 
Devonian strata and fossils 405. 
Dextral univalves 23. 
Dextrorsity 108. 
Dialyneury 222. 
Dichodroma 285. 
Dichoglossa 271, formula 271. 
Dichoriza 343. 
Dicecia 25, 141, 351, cryptophallia 353, 
exophallia 352. 
Diffusion 390. 
Digestive gland 138, I40, 245, 279, 
Anodonta 173, elements of 140, 173, 
ferment of 280, function 154, 173, 
280, Helix aspersa 154, lobule of 
173, Limnwa stagnalis 279, struc- 
ture 154, 173. 
Dignatha 250, 2-52. 
Digitate glands in Helix aspersa 162. 
Dimorphism 26, 71, 353. 
Dimya (see Isomya). 
Diotocardia 291. 
Diotocardiate pelecypod 302. 
Discoidal univalves 25. 
Dispathostyla 368. 
Distomatism 119. 
Distribution, bathymetrical 390, geo- 
graphical 385, geological 403, hypso- 
metrical 390, of pentatienia 389, sub- 
dominant helicidre 389, vertical 390. 
Ditremata 355. 
Diurnal range, heart pulsation 157, 200. 
Divination by snails 434- 
Donax, lleche tricuspide 278. 
Dorsal (see Pallial region), cuticle 157, 
eyes 230, 233, 234, grooves 205, mar- 
gin of bivalves 36. 
Dreissensia piolijmorpha, alimentary 
tract 277 , form 39, 51, 52, labial palps 
101, ligamental pit 48, markings of 
shell 50, muscle scars 10, muscular 
system 347, otocysts 24I, periodicity 
301, podium 45, veligerous stage 
382, vestigial foot 195, vision 236. 
Dyaster or twin stars 379. 
