- Saxicava rugosa.
- S. gallicana.
- S. veneriformis.
- S. pholadis.
- S. Australis.
- · · · · ·
- S. distorta.*
- S. rhomboides.*
- S. carditoides.*
- S. californica.*
2. Genus Petricola. Pl. [VII].
Animal. Unknown.
Shell. Subtrigonal, more or less irregular, transverse, inequilateral; upper side narrowed and a little gaping; lower side rounded; hinge with two teeth in each valve, or in one valve only. Inhabits the Australian seas, boring into wood and rocks. Thirteen species.
- Petricola lamellosa.
- P. Ochrolenca.
- P. Semilamellata.
- P. lucinalis.
- P. striata.
- P. costellata.
- P. recellaria.
- P. exilis.
- P. ruperella.
- P. chamoides.
- P. pholadiformis.
- P. labagella.
- P. linguatula.
3. Genus Venerirupis. Pl. [VII].
Animal. Unknown, but probably resembling the Venus.
Another lithophagous shell, taken from the genus Venus, and distinguished from it by the different disposition of the teeth.
Shell. Transverse, inequilateral, posterior side short, the anterior gaping slightly. Hinge with two teeth on the right valve, three on the left, and sometimes three on both—these are small, near together, and parallel. Ligament exterior. Inhabits the British seas, boring into rocks and clay. Eight species.
- Venerirupis perforans.
- V. nuclea.
- V. Ira.
- V. corditoides.
- V. exotica.
- V. distans.
- V. crenata.
- V. alata.