3LASS IV 



GASTROPODA 



23 



Euphemus M'Coy (Fig. 849). Differs from Bellerophon in tlie revolving folds of 

 the inner lip. Carboniferous. 



Bucanopsis Ulricli. Ordovician to Permian. 



Warthia, Mogulia, and Stachella Waagen. Carboniferons. 



Fig. 849. 



Euphemus nrii Fleming. Lower 

 Carboniferous ; EdinburKh. 



Fig. 850. 



Carinarojms cymhula Hall. 

 Ordovician ; Kentucky. 



Family 8. Carinaropsidae Ulrich and Scofield. 



Symmetrical, almost patelliform shells of not more than two volutions with greatly 

 expanded aperture within which is a hroad concave septum. 



Garinaropsis Hall (Phragmostoma Hall, non Waagen) (Fig. 850). Dorsum carinate ; 

 slit band occasionally distingiüshable. Ordovician and Silurian. 



Suborder B. RHIPIDOGLOSSA Troschel. 



{Scutihranchiata Ciivier ; Zygohranchia and Diotocardia von Ihering.) 



Symmetrical and limpet-like or with spiral shells. GUIs pliime-Uke, two and sym- 

 metricalf or single. Radula with several large plates or teeth in the median portion, and 

 excessively numerouSj crowded, narrow, hooh-shaped teeth. Operculum often present. 



The Rhipidoglossa comprise both air-breathing and aquatic forms, and are divisible 

 into two series : Zygohranchia, in which two gills are developed, and the shell is 

 generally perforated at the apex or has a slit in the outer lip ; and Anisohranchia, 

 with a Single gill and generally unslit shell. 



Family 1. Haliotidae Fleming. 



Shell flattened, auriform, with wide aperture, and no operculum. Interior nacreous, 

 with a row of perforations on the left outer margin. Marine. Cretaceous to Recent. 



Haliotis Linn. This, the solitary genus, occurs very rarely fossil except in the 

 Quaternary. 



Family 2. Pleurotomariidae d'Orbigny. 



Shell spiral, sub-spherical, turhinate, conic, turreted or Planorhoid, nacreous inter- 



li 



Fio. 851. 

 / "- {Raphistomdia) nulians Wissm. Keuper ; St. Cassian, Tyrol. B, Pleurotomaria 

 (Cryptaenia) imlita Goklf. Lower Lias ; Göppingen, Würteniberg. 



