470 MOLLUSCA SUB-KINGDOM VI 
emargination or faint canal. Inhabits only brackish water or estuaries. Cretaceous 
to Recent. 
Sub-genera: 7'ympanotomus, Adams (Fig. 934); Pyrazus, Telescopium, Montf.; Cerithidea, 
Swains.; Lampania (Fig. 935) ; Pyrenella, Gray ; Sandbergia, Bosq. 
Family 18. Aporrhaidae. Philippi. 
Shell fusiform, turreted, or conical ovate. Aperture produced anteriorly in a canal. 
Outer lip expanded in a wing-like or digitiform fashion, or thickened. Operculum horny. 
Marine. Jura to Recent ; maximum in Jura and Cretaceous. 
Alaria, Morris and Lye. (Figs. 936-938). Shell turreted; aperture 
with long or short canal. Outer 
lip not overriding the last whorl, 
digitated or winged. Spire and 




Fic. 937. Fic. 939. 
Fic. 936. Alaria armata, Morris SRE: Spinigera — semicari- 
Alaria myurus, Deslongch. and Lye. Great Oolite ; Alaria (Anchura) cari- nata, Goldf. sp. _Callo- 
Lower Oolite; Bayeux, Minchinhampton, Eng- mata, Mant. Gault; vian; Montreuil-Bellay, 
Calvados. land. Folkestone, England. Maine-et-Loire. - 
body whorl often retaining traces of apertures at earlier stages. Very abundant in 
Jura and Cretaceous. 










Sub-genera: Dicroloma, Gabb; Anchura, Conrad 
(Fig. 938). Jura and Cretaceous. Diempterus, Piette. 
Jura. 
Spinigera, VOrb. (Fig. 939). Whorls keeled 
and ornamented with two opposite rows of spines. 
Jura. 
Aporrhais, da Costa (Chenopus, Phil.), (Figs. 
940-942). Like Alaria, but margins of aperture 
elongated posteriorly in a canal, which remains 
Fic. 941, 

Aporrhais (Dimor- Fic. 942. 
Fic. 940, phosoma) calearata, : ‘ ae 
eas Sowb. Upper Aporrhais (Lispodesthes) Reussi, Geinitz var. 
Aporrhais tridactylus, A. Braun. Oligo- Greensand; Black- megaloptera, Reuss. Pliner; Postelberg, 
cene ; Hackenheim, near Creuznach. down, England, Bohemia. 
either attached to the spire, or extends free from the same. Outer lip expanded, 
digitated, or lobed. Jura to Recent. 
