sri:-()HDER A 



TECTIBRANCHIATA 



48' 



Bulla, Klein (Fig. 1015). Oval, inllat.-d, with .sunken spire and perforate n\-\. 

 A]>.-rture rounded posteriorly and anteriorly. Jura(?) to Recent. 



Family 6. Tornatinidae. 



Radula unarmed. Tertiary and Recent. 



Tornatina, Adams (Fig. 1016). Cylindrical, with projecting 

 spire, and sinistral, tilted nucleus. Coluim-lla 

 bearing a single fold. Tertiary and Recent. 



Retusa, Brown. Shell resembling Cylichna. 

 Tertiary and Recent. 



Volvula, Adams (Volvulella, Newton). Fusi- 

 FIO. ioi6. form, the body whorl forming a point above the 



spire. Eocene to Recent. 



Tornatina exerta, 

 Desh. Oligpcene; 

 Jeurres, near Etampes 

 (after Deshayes). 



um. 



Hull, i itinpiilln, Linn 

 Asti, Italy. 



Family 7. Scaphandridae. 



Spire concealed ; radula with few teeth in a row. Trias to Recent. 



Scaphander, Montf. (Fig. 1017). Shell sub-cylindrical, with epidermis, usually 

 spirally striated. Body whorl of enormous capacity, much dilated 

 anteriorly. Columella spiral, leaving a false umbilicus. Cretaceous 

 to Recent, 



Atys, Montf. Cretaceous to Recent. Diaphana, Brown. 

 Tertiary and Recent. Smaragdinella, Adams. 

 Recent. 



Cylichna, Loven (Bullinella, Newton), (Fig. 

 1018). Small, cylindrical, solid ; spire deeply 

 perforated at the summit ; body whorl covering 

 all the others. Aperture very narrow, outer 

 margin longer than the axis of the shell. 

 Columella thickened anteriorly and bearing a 

 small plication ; often umbilicated. Trias to Flf;- 1017 



Recent. 



FIG. 1018. 



Cylichna conoiden, 

 Desh. Oligocene; 

 Weinheim, near Alzey. 



Family 8. Philinidae. 



Scaphander conicits, 

 Desh. Eocene ; Brack- 

 lesham, England. 



Similar to Scaphandridae, but shell internal, loosely coiled, punctate. Cretaceous to 

 Recent. 



Philine, Ascan. (Bullaea, Lam.), (Fig. 1019). Cretaceous to 

 Recent. 



Family 9. TJmbraculidae. 



FIG. 1019. 

 Shell orbicular, broad, Desh. Eocene.' 



Shell limpet -shaped, with low sub -central apex, and sharp, thin 

 edges. Tertiary and Recent. 



Umbraculum, Schum. (Umbrella, Lam.). 



patelliform ; ornamented exteriorly with concentric lines of growth ; in- 

 ternal surface with concentrically undulating striae. Eocene to Recent. 



Other families of Tectibranchiata, such as Aplysiidae, Pleurobranchidae, etc., are 

 represented in the recent fauna, but their thin, often membranous shells have not been 

 found fossil. The supposed Aplysias reported from the Pliocene by Philippi are 

 flakes from the interior of Pelecypod valves. 



