SUB-CLASS II PLATYPODA—EUTHYNEURA 483 
Borsonia, Bellardi (Fig. 1000). Outer margin with a shallow notch; canal long 
and straight; columella with one or two folds; operculum unknown. Eocene to 
Recent. 
Mangilia, Risso (Figs. 1001, 1002). Small, fusiform, imperforate, and typically 
with longitudinal costae or swellings. Aperture commonly narrow, with a short, 

Fic. 1002. 

A, Mangilia (Clathur- 
ella) strombillus, Duj. Fie. 1003. 
Fia. 1000. 
; : Frc. 1001 Miocene ; Kienberg, Daphnella (Raphi- 
Borsonia Deluci, : 5 near Vienna. 3B, M. toma) vulpecula, 
Nyst. Lower Oligo- Mangilia angusta, (Homotoma) reticulata, Brocchi. Pliocene ; 
cene; Lattdorf, near Jan. Pliocene; Brocchi. Pliocene; Sassuola, near 
Bernburg. Occiano, near Pisa. Sassuola, near Modena. Modena. 
truncated canal; inner margin varicose ; sinus near the suture. Outer margin usually 
somewhat thickened, posteriorly with shallow notch. Tertiary and Recent. 
Allied genera are the following :—Clathurella, Carp. (Fig. 1002, A); Homotoma 
(Fig. 1002, B); Atoma, Bellardi; Daphnella, 
Hinds, with sub-genus Raphitoma, Bellardi (Fig. 
1003); Hucythara, Fischer, ete. 
Family 4. Conidae. Adams. 
Shell convolute, turbinate, or sub-cylindrical, 
generally smooth. Spire short, conical or flattened. 
Aperture long, narrow, anteriorly notched. Outer 
lip sharp, sometimes with an anal sinus below the 
suture. Columella smooth.  Operculum horny. 
Cretaceous to Recent. 
This family is now enjoying its acme of 
development, having entered upon its ascendency 
during the Tertiary. The typical genus Conus, 
Linn. (Fig. 1004), is divided by malacologists 
into numerous sub-genera, connected with one Le cots: AONAEronee Been MEN eoeaLb 
another by intermediate forms. It is initiated in Lapugy, Transylvania. 3B, C. _ parisiensis, 
the Cretaceous. ae Caleaire Grossier; Grignon, near 
Conorbis, Swains. Characterised by a_ high 
spire, and a curved, outer lip, which is deeply notched posteriorly. Eocene and 
Oligocene, 

Pia. 1004. 
Sub-Class 2. EUTHYNEURA. Spengel. 
Gastropods in which the visceral nerve commissures are not crossed, but form a simple 
loop ; the sexes are united (hermaphrodite) ; and the heart is often in front of the gill. 
Shell spiral or swucer-shaped, frequently vestigeal or absent ; operculum generally wanting. 
Radula generally multiserial. 
