8o6 NORTH AMERICAN INDEX FOSSILS. 



OPISTHOBRANCHIA. 



Family Act^onid^: d'Orbigny. 



CXCVII. Tornatelljea Conrad. 



Shells with short, thick spire of rounded whorls, embracing 



half way or more ; aperture with both anterior and posterior notch. 



Columella with two plications near the front and outer lip thick 



and crenulated near the margin. Surface strongly spiraled. 



Jurassic-Miocenic. 



639. T. lata Conrad. Eocenic. 

 Aperture more than half the length of the entire shell; colu- 



mellar plications distant; spirals rounded and close together. 

 Eocenic of Shark River, New Jersey, and of Alabama. 



640. T. bella Conrad. (Fig. 1185,0.) Eocenic. 

 Less ventricose than preceding; sutures less pronounced; inter- 

 spiral depressions punctate. 



Eocenic (Pamunkey) of Maryland and Virginia; Midwayan 

 and Chickasawan of Gulf region. 



CXCVIII. Action Montford. 



Shell with sinistral protoconch differing from Tornateilcua 



chiefly in the deeper sutures and consequently 



W:M more pronounced whorls of the spire and in 



||||f having only one plication on the columella. 



Cretacic-Recent. 

 Fig. 1 1 84. Actceon 



attenuates, view of the 641. A. attenuatus (M. and H.). (Fig. 1184.) 



type and surface en- Cretacic. 



larged. (After Meek.) Sma ^ whorls elongate, slightly convex ; 



suture scarcely depressed but distinct ; surface with spirals and 

 faint growth lines. 



Pierre of Yellowstone River and Canada. 

 642. A. shilohensis Whitfield. (Fig. 1185, b.) Miocenic. 



Spire appearing almost steplike from impressed sutures, rather 

 short; body whorl ventricose with narrow, long aperture; spirals 

 alternating, obsolete above the middle of whorl ; plication pro- 

 nounced. 



Shiloh marls of New Jersey; Chesapeakean of Maryland. 



