| When a concavo-convex plate is affixed to the outside of the cubit. |
| F is called a meniscus, or concavo-convex, being concave on one, and convex on the other side. |
| Grain is oblong, obtusely trigonous, or concavo-convex, red-brown and rugulose on the ventral side. |
| Grain is orbicular to ovate, concavo-convex, red-brown, and transversely rugose. |
| These two genera have concavo-convex profiles, with strongly convex ventral valves, whereas the new genus is plano-convex and has a gently convex ventral valve. |
| They are neat, moderately thin, concavo-convex disks, with smooth surfaces and rounded edges. |
