SUB-ORDER A TECTIBRANCHIATA 487 
Bulla, Klein (Fig. 1015). Oval, inflated, with sunken spire and perforate apex. 
Aperture rounded posteriorly and anteriorly. Jura (?) to Recent. 
Family 6. Tornatinidae. Fischer. 
Radula unarmed. Tertiary and Recent. 
Tornatina, Adams (Fig. 1016). Cylindrical, with projecting 
spire, and sinistral, tilted nucleus. Columella 
bearing a single fold. Tertiary and Recent. 
Retusa, Brown. Shell resembling Cylichna. 
Tertiary and Recent. 

Volvula, Adams (Volvulella, Newton). Fusi- Fic. 1015. 
Fic. 1016. form, the body whorl forming a point above the — gytia ampulla, Linn. 
Tornatina exerta, Spire. Eocene to Recent. Pliocene ; Asti, Italy. 
Desh. Oligocene; 
Jeurres, hear Etampes 
(after Deshayes). Family 7. Scaphandridae. 
Spire concealed ; radula with few teeth in a row. Trias to Recent. 
Scaphander, Montf. (Fig. 1017). Shell sub-eylindrical, 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, Lovén (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. 

Fic. 1018. Columella thickened anteriorly and bearing a Z 
Cylichna conoidea, small plication; often umbilicated. Trias to Fic. 1017 
Desh. Oligocene ; 1G. 1017. 
Weinheim, near Alzey. Recent. Scaphandon  conicus 
Desh. Eocene; Brack- 
lesham, England. 
Family 8. Philinidae. 
Similar to Scaphandridae, but shell internal, loosely coiled, punctate. Cretaceous to 
Recent. 
Philine, Ascan. (Bullaea, Lam.), (Fig. 1019). Cretaceous to 
Recent. 
Family 9. Umbraculidae. 

Shell limpet-shaped, with low sub-central apex, and sharp, thin 
edges. »Tertiary and Recent. Fic. 1019. 
= . , : - ‘ Philine excavata, 
Umbraculum, Schum. (Umbrella, Lam.). Shell orbicular, broad, Desh. Eocene. 
patelliform ; ornamented exteriorly with concentric lines of growth ; in- eoeaee Aa TOBEe i 
ternal surface with concentrically undulating striae. Eocene to Recent. ~ 
Other families of Tectibranchiata, such as Aplystidae, Plewrobranchidae, ete., 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 Peleeypod valves. 
