INDEX. 
XV 
Order I.— ACEPHALA TESTACEA— (cdh^iWi/). 
Rudista, 83 
Radiolites, 83 
Sphserulites, 84 
Calceola, 84 
Hippurites, 84 
Batolithes, 84 
Ostrea, 84 
Ostrea proper, 84 
Peloris, 84 
Gryphaea, 85 
Pectens, 85 
Lima, 86 
Pedum, 86 
Hinnita, 86 
Plagiostoma, 87 
Pachytes, 87 
Diancliora, 87 
Podopsis, 87 
Anomia, 87 
Echion, 87 
Placuna, 88 
Spondylus, 88 
Plicatula, 88 
Malleus, 88 
Vulsella, 89 
Perna, 89 
Crenatula, 89 
Gervilia, 89 
Inoceramus, 90 
Castillus, 90 
Pulvinites, 90 
Etheria, 90 
Avicula, 90 
Pintadime, 90 
IMargaritae, 90 
Pinna, 91 
Chimaera, 91 
Area, 91 
Area proper, 92 
Cucullsea, 92 
Pectunculus, 92 
Aximea, 92 
Nucula, 92 
Trigonia, 93 
Fam. 2, — Mytilacea, 93 
Mvtilus, 93 
Mytilus 23roper, 93 
Modiolus, 94 
Lithodomus, 94 
