21, 22. M. costata, Pennant, (Murex.)—Buccinum, Fusus, Pl. c., etc.; var. f. 22, M. Metcalfei.—Brit co. generally, 5 to 50 fath., N. and S. Eu., C. Body-whorl larger than No. 24.
23. M. coarctata, Forbes.—Pl., M. costata var., B. M.—Distribution as 21 and 22; not so common.
24. M. septangularis, Mont. (Murex.)—M., F., and Pl. costatus, heptagona, etc.—Torbay, Bristol Channel, Forth, Galway, 5 to 30 fath., Mc.
25. M. attenuata, Mont. (Murex.)—M. aciculatus, Pl. gracilis, Villiersii, etc.—S. Devon, Oban, Hebrides, Cork, etc., Mr. S. Eu.
26. M. gracilis, Mont. (Murex)—M. emarginatus, suturalis, elegans, etc., S. Brit., Galway, S. Eu., Mr.
M. Holbollii. See Buccinum.
Erato.
27. E. lævis, Donovan, (Voluta.)—E., Marginella, Bulla, Volvaria, and Columbella fusiformis, Cypræola, Donovani, Muscaria, etc.—Brit. co. generally, 1 to 50 fath., Mc.
Cypræa.
28. C. europæa, Mont.—Cypr. and Trivia, Pediculus arctica, bullata, and diaphana.—Brit. co. generally, 0 to 50 fath., C.