CONCHOLOGY. 
31. Astarte. Shell orbicular or subtriangular, 
equivalve, closed. Hinge with two teeth in each 
valve, with very obscure lateral ones. 
Includes Venus scotica, danmonia, Mactra 
triangularis and minutissima. 
32. Myrtea. Shell oval-triangular, equivalve, 
closed. Hinge of one valve with a single tooth 
and lateral one each side of the other valve with 
‘two teeth and obscure lateral ones. 
Includes Venus spinifera, 
32. Cyprina. Shell somewhat heart-shaped, 
‘equivalve, closed. Hinge with two or three teeth 
‘divergent at their tips, and a lateral one at the 
anterior side, 
Includes Venus Islandica, triangularis, minima, 
33. Venus. Shell transverse or somewhat orbicu- 
lar equivalves, closed. Hinge with three teeth in each 
valve, the outer ones close together at the base 
and divergent at their tips: lateral teeth none. 
Includes Venus verrucosa, Casina, reflexa, 
fasciata, laminosa, Gallina, ovata, aurea, virginea, 
decussata, pullastra. 
34. Cytherea, Shell suborbicular or transverse, 
equivalve, closed. Hinge with four teeth in the 
right valve, three of them close together at the 
base, and one remote under the areola; in the left 
valve three teeth, rarely four, close together, 
with a remote cavity on the anterior side; lateral 
teeth none. 
Includes Venus Chione, exoleta, sinuata, and 
tigerina, 
B 
