PLATE VII. 



Unio. Fresh-water Mussel with hinge-teeth. 

 Fig. 



1. U. margaritieerus, Linn. (My a.) — Alasmodon m., A.arcuata, U. 



elongata, U. sinuata. — R. Conway ; rivers in Cumberland, Wales, 

 Ireland, etc., Mc. Long, thick, arched. 



2. U. pictorum, Linn. (Mya.) — U. ovalis, U. rosirata, U. limosus, U. 



Deshayesii, etc. — Various British rivers, C. Long, oval, not 

 wedge-shaped behind. 



3. U. tumidtjs, Retz. — Mya and Unio ovalis, M. depressa, M. ovata, 



Myscei o., M. solida. — Thames, and various British rivers, C. 

 More solid, deep, and wedge-shaped than U. pictorum. 



Anodonta. Fresh-water Mussel, without teeth. 



4. A. CYGNEa, Linn. (Mytilus?) — M. anatinus, M. stagnalis, M. pa* 



Indosa, Symphonota cy. — Britain and Europe generally, in rivers 

 and canals, C. 



DreIssina, Beneden. 



5. L\ polymorpSa, Pallas, (Mytilus.) — London Docks, Edinburgh 



Canal, C. 



Modiola, Lamarck. 



6. M. Modiolus, Linn. (Mytilus.) — M. umbilicatus, M. curtus, M. 



vulgaris. — British coasts generally, C. Large, brown, not rayed. 



7. M. ovalis?, Sowb. — M. tulipa (radiata), var., Brit. Moll., now 



named provisionally. Less tumid, and with longer and more 

 gradually sloped dorsal line than M. radiata, Er. 



8. M. radiata, Ranley, Brit. Marine Conch. — M. tulipa, Brit. 



Moll, Mc. Tumid, radiated. 



9. M. barbata, Linn. (Mytilus.) — M. Gibbsii. — Jersey, Torbay, Mil- 



ford Haven, Youghal, R. as Brit. Barbs of epidermis serrated. 



10. M. phaseolina, P/dlippi. — Guernsey, Ealmouth, Scotland, Mc. 



Small barbs of epidermis not serrated. 



11. M. cuprea, Jeffreys, Ann. Nat. Hist. Jan. 1859. — In the stomach 



of a bird shot at Scarborough, Rr. Minute, rhomboidal, smooth. 



Crenella, Brown. 



12. C. nigra. Gray, (Modiola)) — Mytilus and Modiola discrepant, de- 



pressa, compressa, discors. — Scotland, R. Broad and compressed 

 behind) 



