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 : Pwpina 

 (subg. Registoma, Callia, Streptaulus, Fupinella, Anauhis), Hylo- 

 cystis (Fig. 205, p. 305), Cataidus, Coptochilus, Megalomastoma. 

 (iv.) Cyclophorinae, shell turbinate or depressed, operculum corne- 

 ous or calcareous. Genera : Alycaeus, Craspedopoina, Lepto2')oma, 

 Lagochilus, Cyclophorus (Fig. 206, p. 306; including Diadema, 

 Aulopoma, Ditropis, and others), Aperostoma (including Cyrtotoma 

 and others), Cyathop)oma, Ptcrocychis (subg., Myxostoma, Spira- 

 cidurii, OjnsthojJonis, and Bhiostovia (Fig. 180, p. 266), Cyclotus, 

 Cydosurus, and Stropliostoma. 



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

 monary sac, tentacles obtuse, foot with a deep longitudinal median 

 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 calcareous and 

 an internal cartilaginoid lamina, rarely 

 corneous. Terrestrial only. Cretaceous 



. Genera : Cydostoma (subg., 



Leonid, Trojndophora, Bochebrunia, 



Fig. 21 a. — Cydostoma cam- Georgia, Otopoma, Litlddion, Bevoilia'), 



panulatnm Pfr., Mada- Cyclotopsis, Chomiopoma (subg., Licina, 



Jamaicia, Ctenopoma, Biplopoma, Adam- 



siella), Cistula (subg., Chondropoma, Tudura), O)nphalotrop)is (subg., 



Realia, CydomorpluC), Hcdnesia, AcroptycMa. 



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 very similar,pinched 

 in at the sides, external marginal broad, edge finely pectinate ; 

 shell small, acuminate, with a blunt spire, operculum corneous. 



Terrestrial only. Tertiary . Genus, Acicida {^=Aeme). 



Fam. 15. Trunccitellidae. — Ctenidium replaced byapidmonary 

 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., Taheida, 



Blanfordia, and Tomichia), Geomelania (subg., Chittya and 

 Blandiellci), Cecina (?). 



