426 



MONOTOCARDIA — TOXOGLOSSA 



CHAP. XIV 



operculum present or absent. Cretaceous- 



40.^: 



— . Principal 

 genera: Oliva (Figs. 283, and 98, p. 199), 

 Olivancillay'ia (including Lintricula and 

 Agaronia)^ Olivella, Aneilla (subg., Ancil- 

 lina). 



(e) ToxoGLOSSA (p. 218). — Radula with 

 normal formula l-O-l, teeth large ; oesophagus 

 with a large poison gland ; animal carnivo- 

 rous, exclusively marine. 



Fam. 1. Terebrldae. — Eyes at the end of 

 the tentacles, shell subulate, 

 many whorled, operculum 

 with terminal nucleus. 



Eocene . Single genus, 



Terebra, with several sec- 

 tions. 



Fam. 2. Conidae. — Eyes 

 on outer side of tentacles, 

 siphon prominent ; shell 

 conical or fusiform, aperture 

 narrow. Cretaceous . 



Principal genera: Conus, shell solid, spire 



short, aperture narrow, straight, internal par- 

 titions partly absorbed ; Conorhis^ Genotia 



(with several sections, chiefly Tertiary), 



Pusionella^ Columbarium^ Clavatula, Surcula^ 



Pleurotoma ; Borsoiiia (Eocene), Drillia 



(subg., Spwotropis)^ Bela^ Mangilia (including 



DapJmella, Clathttrella, and others), Halia. 



Fam. 3. Cancellariidae. — Proboscis short, usually no 



radula, shell oval, columella strongly plicate ; no operculum. 



Cretaceous . Single genus, Cancellaria (subg., Merica^ 



Trigonostoma^ Admete). 



Fig. 284.— rere6m suh- 

 ulata L., Ceylon. 



Fig. 285. — Pleuro- 

 toma tigrina Lam., 

 E. Indies. 



