DIVISION XIII. 
GENERA. 
A. In the form of a shield or cap. 
4. Carutus. Mont. 
Conical, the summit 
curving spirally. Pl. 5, 
fight ton 
2. Hirponyx. (1) De 
France. 
Conical, summit in- Support adherent and 
clined backwards. Pl. 6, bearing (as well as the 
fig. 1. 
shell) a muscular impres- 
sion in the shape of a 
horse-shoe. 
3. CREPIDULA. Lam. 
Oval or oblong, the 
summit obtuse, inclined 
towards the edge. Pl. 5, 
fig. 12. 
Half closed by a ho- 
rizontal plate. 
4. Catyerrma. (2) Lam. 
_Conical, the summit ver- 
tical and pointed. 
MEGASTOMATA. 
Marine. 
Mediterranean. 
badoes. 
V. Animal, p. 71. 
Bar- 
Marine. 
Marine. 
On the rocks of the 
Caribbean Sea. Mediter- 
ranean. 
Y. Animal, p. 72. 
Marine. : 
Atlantic, Indian Seas. 
a The plate (adhering to the bottom of the cone) folded, and descending 
vertically. Pl. 5, fig. 8. 
6 Infundibulum, Montf. The plate simple, almost horizontal, adhering to 
the sides of tbe cone, which has a spiral line on the exterior. Pl. 5, fig. 20. 
5. Umprewta. Lam. 
Orbicular, slightly con- — A callous, colored disk, 
vex above, a small apex within. 
near the summit. Pl. 5, 
fig. 15 
Marine: 
Mediterranean, 
dian Seas. 
Tn- 
(41) Several valves of different sizes having been found at Grignon, in the marl- 
pits of Hauteville, Montmirail, etc. they were considered by some naturalists as 
the type of the genus Acardo. M. Defrance having remarked a similar support 
adhering to a recent shell (Patella mitrata, Gm.), foresaw that some other Patell 
were to be separated from that Genus to form the present. His conjectures were 
afterwards realised by finding one of the fossil species on its support. 
(2) Foss. Grignon. 
(3) Foss. in the London Clay; Crag Marl; Woolwich Loam; Green Sand. 
