Fam. 1. Eulimidae.—Proboscis very long, retractile, mantle forming a siphonal fold; shell small, long, subulate, polished; suture shallow, aperture continuous, operculum present or absent. Animal often parasitic, sucking the juices of its host by its long proboscis. Trias——. Genera: Eulima (subg., Subularia, Arcuella, Apicalia, Mucronalia, Stiliferina, and others), Stilifer, Scalenostoma, Niso, and Hoplopteron.
Fam. 2. Pyramidellidae.—Tentacles auriform, proboscis as in Eulimidae, a prominent mentum or flap under the buccal orifice; shell usually small, conical; suture shallow, apical whorls (the embryonic shell) sinistral (p. [250]), operculum corneous, paucispiral; nucleus excentrical. Trias——. Genera: Pyramidella (subg., Syrnola, Otopleura, Chrysallida, Mumiola), Odostomia, Eulimella, Murchisoniella, Turbonilla (subg., Dunkeria and Cingulina).
(d) Rachiglossa (p. [220]).—Proboscis long, retractile; siphon distinct, radula without uncini, sometimes without laterals; teeth strongly cusped; shell generally wholly external.
Fam. 1. Muricidae.—Eyes sessile at the outer base of the tentacles, penis large, behind the right tentacle, radula 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; Trophon, Typhis, Murex (with many subdivisions), Ocinebra (including Cerastoma, Vitularia, and Hadriania), Urosalpinx, Eupleura, Pseudomurea. (ii.) Purpurinae, nucleus of operculum lateral; Rapana (including Latiaxis), Purpura (with subg., Cuma, Iopas, Vexilla, and Pinaxia), Monoceros (including Chorus), Purpuroidea (Secondary strata), Pentadactylus, Sistrum, Concholepas.
Fam. 2. Coralliophilidae.—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, Coralliophila, Leptoconchus, Magilus (Fig. [29], p. 75), Rapa.
Fam. 3. Columbellidae.—(Radula, Fig. [123], p. 222.) Shell small, solid, fusiform, aperture narrow, canal short, outer lip thickened. Miocene——. Single genus, Columbella (subg., Nitidella, Anachis, Meta, Strombina, Atilia, Conidea, Amphissa, Mitrella, and others).
Fam. 4. Nassidae.—Foot long and broad, often with terminal appendages; siphon long, eyes on outer base of tentacles, 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 thickened, often toothed; operculum corneous, edges often toothed. Miocene——. Principal genera: Nassa (with many sections), Amycla, Desmoulea, Cyclonassa, Canidia (subg., Clea and Nassodonta), Dorsanum, Bullia (= Buccinanops, 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 fusiform, 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, Jumala), subg., Sipho; Siphonalia (subg., Kelletia). Group ii. Liomesus (= Buccinopsis). Group iii. Buccinum (Fig. [1] B, p. 6; subg., Volutharpa, Neobuccinum). Group iv. Cominella, Tritonidea, Pisania, Euthria; Anura (Miocene), Genea (Pliocene), Metula, Engina. Group v. Phos, Hindsia. Group vi. Dipsaccus (= Eburna), Macron. Group vii. Pseudoliva.
Fam. 6. Turbinellidae.—Central tooth of radula tricuspid, median cusp strong, lateral bicuspid, cusps unequal (Fig. [117], p. 220); shell fusiform or pear-shaped, heavy, canal often long, operculum corneous, claw-shaped, nucleus terminal. Miocene——. Principal genera: Turbinella, Cynodonta, Tudicla (subg., Streptosiphon); Piropsis (Cretaceous), Perissolax (Cretaceous), Strepsidura (Eocene, subg., Whitneya), Melapium, Fulgur (= Busycon, Fig. [150], p. 249, including Sycotypus), Melongena (subg., Pugilina, Myristica); Liostoma (Eocene), Hemifusus (subg., Megalatractus), Ptychatractus, Meyeria.
