XIV MONOTOCARDIA — RACHIGLOSSA 423 



Fam. 1. Muricidae. — Eyes sessile at the outer base of the 

 tentacles, penis large, behind the right tentacle, raclula within 

 the retractile proboscis, central tooth (Fig. 119, p. 220) with at 

 least three strong cusps, laterals plain ; shell solid, more or less 

 tuberculate, spiny and varicose, anterior canal varying from a 



mere notch to a long channel. Cretaceous . Principal 



genera : (i.) Muricinae^ nucleus of operculum sub-terminal ; Tro- 

 phon^ Typhis^ Murex (with many subdivisions), Ocinehra (includ- 

 ing CWastoma, Vitularia^ and Hadriania)^ Urosalpinx^ Eupleura^ 

 Pseudomurea. (ii.) Purpiirinae^ nucleus of operculum lateral ; 

 Rapana (including Latiaxis^^ Purpura (with subg., Cuma^ lopas, 

 Vexilla^ and Pinaxia)^ Monoceros (including Chorus^ ^ Purpu- 

 roidea (Secondary strata), Pentadactylus^ Sistrum, Concholepas. 



Fam. 2. Coralliop>hilidae. — Animal living in Madrepores, 

 resembling Purpura^ radula absent ; shell variously shaped, 

 often deformed or tubular, operculum that of Purpura^ if 



present. Miocene . Principal genera : Rhizochilus^ Co- 



ralliophila^ Leptoconclius^ Magilus (Fig. 29, p. 75), Rapa. 



Fam. 3. Columhellidae. — (R?idi\A^, Fig. 123, p. 222.) Shell 

 small, solid, fusiform, aperture narrow, canal short, outer lip 



thickened. Miocene . Single genus, Cohwibella (subg., 



Nitidella^ Anachis, Meta, Strombina, Atilia, Conidea, Amp^hissa, 

 Mitrella, and others). 



Fam. 4. JVassidae. — Foot long and broad, often with 

 terminal appendages ; siphon long, eyes on outer base of tenta- 

 cles, central tooth of radula arched, multicuspid, lateral strongly 

 bicuspid, with small denticles between the cusps; shell rather 

 small, buccinoid, columella more or less callous, outer lip thick- 

 ened, often toothed; operculum corneous, edges often toothed. 



Miocene . Principal genera: iVassa (with many sections), 



Amycla^ Desmoulea, Cydonassa, Canidia (subg., Clea and Nasso- 

 donta), Dorsanum, Bullia (^ = Baccinanops^ Fig. 62, p. 185), 

 Truncaria. 



Fam. 5. Buccinidae. — Siphon rather long, eyes at outer base 

 of tentacles ; central tooth of radula with 5 to 7 cusps, laterals 

 bicuspid or tricuspid (Fig. 118, p. 220) ; shell more or less fusi- 

 form, thick, covered with a periostracum, canal of varying length, 

 outer lip simple or thickened; operculum corneous, nucleus 



variable in position. Cretaceous . Principal genera : Group 



i. Chrysodomus (with sections Neptunea^ Volutopsis, Pyrolofusus, 



