PLATE I. 



Teredo. Pierces and inhabits wood. 

 Fig. 



1. T. NAVALis, Linn. — T. Batavm. — Heme Bay, R. Pallets shell j^, 



crescented ; valves with auricles extended sidewise ; tube long. 



2. T. NORVEGiCA, Spengl. — T. Bnujuieri. — Port Patrick, Teignmoutli, 



etc., Mc. Pallets shelly, not crescented ; auricles not extended. 



3. T. MEGOTARA, Kcinl. — T. nana (young) . — Heme Bay, Devon, 



Swansea, etc., R. Pallets shelly, spade-shaped ; auricles raised 

 and expanded. 



4. T. BiPENNATA, TuH. — Ireland, Scarborough, etc., R. Pallets horny, 



long ; auricles lobed. 



5. T. MALLEOLUS, Turt. — Torquay, Rr. Pallets shelly, mallet-shaped ; 



valves narrow. 



6. T. PALMULATA, Lamk. — T. lipalmulata. — Floating wood. Ire., S. 



Eng. Pallets horny, short ; valves small, shaped like T. navalis. 



Xtlophaga. In fixed and floating timber. 



7. X. DORSALis, Turt. — Ayrs., Dubl., Exm., Scarb., etc., C. Two 



dorsal plates, no tube, no pallets. 



Pholas. Pierces and inhabits stone. 



8. P. Dactylus, Li7in. — P. Mans, P. callosa. — Eng., Scot., Ire., C. 



Dorsal plates four ; hinge pitted. 



9. P. CANDIDA, Linn. — Eng., Scot., Ire., C. One dorsal plate ; valves 



not beaked. 



10. P. PARVA, Penn. — P. callosa, P. tnherculata. — Salcombe, Belfast, 



Cornwall, etc., M. C. One dorsal plate; valves beaked. 



11. P. CRisPATA, Linn. — P.bifrons. — Hastings, Liverp., Scarb., Dubl., 



Forth, etc., C. No dorsal plate; valves broad, beaked, with 

 obHque division. 



13. P. STRIATA. Rare and doubtful as British. Valves closed. 



Pholadidea. Pierces and inhabits stone. 



12. P. PAPYRACEA, p. Loscombinna, P. Goodalli. — S. Devon, N. Ire., R. 



Valves closed, with a cup. P. lamellata, Turt., when young, 

 not closed ; no cup. 



GASTROCH.a;NA. Bores and inhabits stone, thick shells, etc. 



14. G. MODiOLiNA, Lamk. — G. PJioladia, G. Mans, Mi/a dahia, Mi/tihn 



ambiguus, Pholas faba. — Torbay, Birterbuy, Galway, Weymouth, 

 etc. Valves thin, gaping, enclosed in bottle-shaped tube. 



b 



