Solen. Burrows perpendicularly in sand. 

 Fig. 



12. S. pellucidus, Penn. — Various British localities, 6 to 100 fath. 



Curved ; hinge not terminal. 



13. S. ensis, Linn. — Eng., Scot., Ire., generally 5 to 15 fath., C. 



Arched and slender. 



14. S. marginatus, Pult. — S. vagina, Penn., not Linn. — Exmouth, 



Clyde, Cork, etc., littoral to 10 fath., Mc. Straight, with ter- 

 minal constriction. 



15. S. siliqua, Linn. — S. novacula, S. ligula. — Eng., Scot., Ire., many 



places ; littoral and laminarian, C. Straight, end not constricted. 



Diodonta. 



16. D. fragilis, Linn. — {Tellina) Psammobia f., Tettina jugosa and 



ochroleuca. — Dublin, Tenby, Weymouth, R. Oval or wedge- 

 shaped. 

 16*. D. Barleei, Jeffr. — Arran, Rr. Minute, subquadrate. 



Solecurtus. 



17. S. coarctatus, Gmel. — S. cultellus, S. emarginatus, S. antiquatus, 



etc. — Torbay, Anglesea, Man, Skye, etc., R. Oblong, smooth. 



18. S. candidus, Eenieri. — {Solen) S. strigilatus, Turt., not Linn., 



Psammobia scopula. — S. Devon, Dublin, etc., R. Striated. 



Syndosmya. 



19. S. PKisMATiCA, Mont. — {Ligula) My a and Amphidesma p. — Wey- 



mouth, Forth, Dublin, Antrim, etc., littoral, Mc. More pointed 

 and narrow than S. intermedia. 



20. S. tenuis, Mont. — {Mactra) Amphidesma t. — Dorset, Scarborough, 



Antrim, etc., 5 to 100 fath., Mc. Short, subtrigonal. 



21 . S. intermedia, Thompson. — Mya and Syndosmya nitida, Abra pro- 



fundissima. — In mud, 6 to 100 fath., Zetland, Skye, Cape Clear, 

 etc., R. Broader and more pointed than S. prismatica. 



22. S. alba, Wood. — {Mactra) M. and Amphidesma Boysii and A. 



album. — Brit. co. generally, C. Short, rounded, oval. 



