414 MONOTOCARDIA— TAENIOGLOSSA chap. 



309), last whorl disconnected, often reflected back upon the 

 spire, (iii.) Pupininae^ shell more or less lustrous, bluntly- 

 conical, lip with a channel above or below. Genera : Pupina 

 (subg., Registoiyia^ Callia^ Streptauliis^Pupifiella^ Anaulus^^ Hyho- 

 cystis (Fig. 205, p. 305), Cataulus, Coptochilus^ Megalomastoma. 

 (iv.) Cy clop Jiorinae, shell turbinate or depressed, operculum corne- 

 ous or calcareous. Genera : Alyeaeus^ Craspedopoma^ Leptopoma^ 

 Lagochiliis^ Cyclopliorus (Fig. 206, p. 306 ; including Diadema^ 

 Aulopoma^ Ditropis^ and others), Aperostoma (including Cyrto- 

 toma and others), Cyatliopoma^ Pterocyclus (subg., Myxontoma^ 

 Spiraculiim^ Opisthoporus, and Rhiostoma (Fig. 180, p. 266), 

 Cyclotus^ Cyclosurus^ and StropJiostoma. 



Fam. 13. Cyclostomatidae. — Ctenidium replaced by a pul- 

 monary sac, tentacles obtuse, foot with a deep longitudinal me- 

 dian groove ; central tooth, lateral, and first marginal more or less 

 bluntly cusped, second marginal large, edge pectinate ; shell 



variously spiral, spire usually elevated, 

 aperture not quite circular ; operculum 

 generally with an external calcare- 

 ous and an internal cartilaginoid lam- 

 ina, rarely corneous. Terrestrial only. 



Cretaceous . Genera : Cyclostoma 



(subg., Leonia^Trop>idophora^ Pochebrunia, 

 Fig. 274^. — Cyclostoma cam- Greoryia^ Otopoma, Litliidion^ Revoilia)^ 

 gascar!^''''' Pfr., Mada- Qyclotopsis, Clioanopoma (subg., Licina, 



Jamaicia^ Ctenopoma^ Piplopoma^ Adam- 

 siella)^ Cistida (subg., Chondropoiyia^ Tudord)^ Omphalotropis 

 (subg., Realia^ CyclomorpJui)^ Hainesia^ Acroptychia. 



Fam. 14. Acicididae. — Ctenidium replaced by a pulmonary 

 sac, tentacles cylindrical, pointed at the end, eyes behind their 

 base, foot long and narrow ; central tooth and lateral ver}^ similar, 

 pinched in at the sides, external marginal broad, edge finely pec- 

 tinate ; shell small, acuminate, with a blunt spire, operculum 



corneous. Terrestrial only. Tertiary . Genus, Acieula 



(^ = Acme). 



Fam. 15. Truncatellidae. — Ctenidium replaced by a pul- 

 monary sac, proboscis very long, eyes sessile, behind the base of 

 the tentacles, shell small, evenly cylindrical, apex truncated in 



the adult. Eocene . Genera : Truncatella (subg., Taheitia^ 



Blanfordia^ and Tomichia^, Creomelania (subg., CJiittya and 

 Blandiella), Cecina (?). 



