192 



terminated by an oblique notch; unequally toothed on the columella and on 

 the internal margin of the right lip, usually contracting the aperture. 



It. horrida, 



' mitieula, 

 ' clathrata, 



R. arachnoidea, 

 ' digitata, 



It. aspera, 

 ' morus, 



It. mutica, 

 ' pisolina. 



Purpura. Shell oval, smooth, 

 the lower part terminating in an obi 

 flattened, pointed at the base. 



P. Persica, P. neritoides, 



Rudolphi, ' planospira, 



patula, ' callifera, 



columellaria, ' coronata, 



succincta, ' carinifera, 



consul, ' scalariformis, 



armigera, ' sacellum, 



bitubercularis, ' squamosa, 



hippocastanum, ' rugosa, 



undata, ' tcxtilosa, 



hajmastomn, ' sertum, 



mancinella, ' Francolinus, 



bufo, ' limbosa, 



callosa, ' ligata, 



tubercular or angular; aperture dilated, 

 ique, subcanaliculated notch. Columella 



P. cruentata, 



' lapillus, 



' imbricata, 



' lagenaria, 



• cateracta, 



1 bicostalis, 



' plicata, 



' fiscella, 



' tliiarella, 



' rustica, 



' semiimbricata, 



' echinulata, 



' liystrix, 



' deltoitles, 



unifascialis, 



retusa, 



trochlea, 



clavus, 



fasciolaris, 



vexillum, 



bizonalis, 



nucleus, 



distorta, 



bulbus, 



subrostrata, 



tectum, 



cariosa. 



Monoceros. Shell oval; aperture longitudinal, the lower part terminating 

 in an oblique notch. A conical tooth on the internal base of the right margin. 



M. cingulatum, M. striatum, M. glabratum, M. crassilabrum. 



' imbricatum, 



Concholepas. Shell inflated oval, semispiral, the summit inclining ob- 

 liquely towards the left margin; aperture large, longitudinal, oblique, with a 

 slight channel at the lower part. Two teeth at the base of the margin; an 

 oblong, thin, corneous operculum. 



C. Peruvianus. 



Harpa. Shell oval, more or less inflated, with longitudinal, parallel, in- 

 clined and acute ribs; spire short; aperture notched at the lower part; no 

 canal. Columella smooth, flattened and pointed at the base. 



Dolium. Shell thin, ventricose, inflated, mostly subglobular, rarely ob- 



