SUB-ORDER B PLATYPODA 479 
oblong, outer margin relatively thin, crenulate; columellar border slightly twisted, 
with two or three small oblique plaits 
anteriorly ; sometimes wmbilicate. Cre- 
taceous to Recent. 
Pisanella, v. Koenen. Oligocene. 
Peristernia, Morch; Leucozonia, Gray. 
Tertiary and Recent. 
Family 6. Turbinellidae. 

Shell similar to those of the preced- 
ing family, but with strong, horizontal 
columellar folds. Tertiary and Recent. 
Fic. 981. 
Latirus craticulatus, 
d’Orb. sp. Miocene ; ie : ree Sth oe 
Lapugy, Transylvania. Turbinella, Lam. (Mazza, Adams ; 
Mazzalina, Conrad). Thick - shelled, 
ovate-conical, smooth; spire short and blunt, body whorl 
large; canal straight, elongated. Eocene to Recent. 
Family 7. Volutidae. Gray. 
Shell thick, ovate to fusiform, dull or lustrous. Spire 
short or long, body whorl large. Aperture elongated, with a 
short canal or notch; inner lip with 
columellar folds.  Operculum usually 
absent. Cretaceous to Recent. 

ATG. GSO. . . . 2 ao. _ » . 
Beg 280 This family, as here defined, contains 
Fasciolaria Tarbelliana,Grat. 
Miocene: Grund, near Vienna, genera distributed by malacologists 
amongst several familes — Marginel- 
lidae, Mitridae, and Volutidae—all of which are characterised by 
the strong development of columellar folds ; 
but it is likely that this structure originated 
independently in several phyla at intervals 
remote from one another. The initiation of 
well-marked genera with Volutoid — plaits 
; = F Marginella crassula, 
occurred in the Cretaceous. Subsequently their pesh.” Calcaire Gros. 
number increased, and a great many generic Sets petenoats EES 
types became differentiated. The phylogeny Sas 
of Tertiary and Recent forms has been ably worked out by Dall! 
Marginella, Lam. (Fig. 982). Shell oval or oblong, smooth, 
glistening. Spire short; aperture narrow, slightly canaliculate 
anteriorly. Columella with three or four oblique folds of about 
equal size; outer margin frequently thickened and dentate. 
Tertiary and Recent. 
Mitra, Lam. (Fig. 983). Fusiform to elongate-oval, solid ; 
spire high, acuminate; aperture narrow, channelled anteriorly. 
Columella with numerous oblique folds, the posterior plaits being 


Fia. 983. often the strongest. Outer margin commonly thickened, and 
Mitra fusiformis, Smooth internally. Abundant in the Tertiary and Recent. 
Seat ye anes Turricula (Klein), Adams. Like the last, but shell transversely 
ribbed. Cretaceous to Recent. 
1 Bull. Museum Comp. Zoology, vol. XVIII., 1889; Proc. U.S. Nat. Museum, vol. XII., 1890 : 
Trans. Wagner Free Inst. Sci. Philad., vol. IIL, 1890. 
