90 F.. B. Meek on Acteonide. 
and C. bullatus, Morris & Lycett; Tornatella Lamarcki, Sowerby, (Ac- 
teonella, Zekeli). (Jurassic and Cretaceous. 
ubgenus Sprracr#on, Meek.—Shell more or less oval, or subfusi- 
form; spire rather prominent, sometimes as long as the body-whorl, con- 
vex in outline on its lateral slopes. Body volution not very ventricose. 
ype :—Tornatella conica, Munster,” (Acteonella, Zekeli). Also in- 
cludes j Theletee elliptica and .A, obtusa, Zekeli; aud Tornatella Voluta, 
Munster, (Acteonella, Deke e, (All ierperss) 
pyriformis, of Morris & pose On com me ES ae it 
will be found to differ materially from that, and all the other 
species included in the group under consideration, in the form of 
the shell. Its columella is also net near so thick nor so straight 
below as in the group here describe 
The differences between these shells and the typical Acieo- 
nellas are, it seems to me, as strongly marked and as constant as 
we can ever expect to see between any two genera of the 
family of Gasteropoda. “ha the first place, in the true Acteonellas 
the whorls are so nearly rolled together upon the same plane 
that there are no traces of a Be and the form is ee 
are this form with the genus under consideration, we find 
the te ne always differs in having the body-whorl turbinate, oF 
widest above the middle, and the spire generally present and &- 
' serted or often elevated. ‘Even in cases, however, where the spire is 
sunken, and its place occupied by an umbilicoid cavity, as is 
sometimes the case in this group, the body-whorl still retains its 
turbinate or obovate form, and the upper extremity of the aper 
ture is never produced upwards, as a kind of canal, over the 
middie of the summit. 
Genus CYLINDRITES, (Auct.) Morris & Lycett. {As agg e 
Shell subeylindrical, or oliviform. Spire generally short, o much 
d or even sunken below the summit of the body-whorl, in 1 which 
latter case the immediate apex usually rises in the form of a nipple in 
“the middle of a saucershaped cavity. Body-whorl Jong, with nearly 
e. 
y 
straight parallel sides which round in to the suture 
ve sh gong often nearly or quite equalling the arene length of the 
shell. Inner lip somewhat thickened, and twisted outwards, so as to fort 
a few obscure folds at the base of the columella. 
2 Goldf. Petrefact,, iii, p. 48, pl. 177, fig. 1-2. 
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