128 GENERA AND SPECIES. 



Murex. (MURICID&.) Plate xxvi. 



506. erinaceus, 2^ in. colour yellowish white, spire turreted. 



507. aciculatus, in. colour reddish brown, spire not turreted. 



Mya. (MYID/E). Plate xii. 



143. arenaria, 4 in. x 2^ in. gaping equally at both ends. 



144. truncata, 2 in. x 2 in. gaping more at posterior end, inside chalky 



white. 



145. binghami, ^ in. x ^ in. gaping at posterior end, inside porcellaneous. 



Mytilus. (MYTILIDJE.) Plate ii. 



19. edulis, i in. x 2^ in. hinge with from 3 to 10 teeth, beaks 



divergent. 



20. modlolus, 2% in. x 5 in. hinge toothless, shell oblong, beaks 



divergent. 



21. barbatus, tin. x i in. hinge toothless, shell triangular, beaks in- 



curved andtlose to point, margins thick. 



22. adriaticus t $in. x i-Jin. hinge toothless, shell oval, beaks incurved 



and remote from point, margins thin. 



23. phaseolinus,^in. x in. hinge finely toothed, beaks incurved. 



There are four varieties of 19, the most marked of which is pellucida, 'which is striped 

 with brown and purple ; of 20 there are two varieties ; of 21 there is a variety which has the 

 upper valve flat and much smaller than the other ; the only variety of 22 is ovalis, which 

 has an almost cylindrical shell quite two inches long. 



Nassa. (NASSID^.) Plate xxvi. 



514. nitida, i in. spire turreted, whorls flat. 



Spire not turreted 



513. retictilato, ij in. whorls convex or flattened, mouth white, 



outer lip with teeth inside. 



515. incrassata, f in. whorls angulated, mouth white or pinkish. 



516. pygmaa, / 5 in. whorls rounded, mouth brown. 



Natica. (NATICIDJE.) Plate xxiii. 



370. islandica, i in. spire produced. 



371. grcenlandica, in. whorls 4 or 5, spire short, umbilicus small. 



372. sordida, ij in. whorls 5 or 6, umbilicus large, spire short, 



mouth equal in length to two-thirds of 

 spire, inner lip brown. 



373. catena, i in. whorls 7, and rounded, spire short, 



umbilicus large. 



374. alderi, f in. whorls 6, spire short, umbilicus small. 



375. montacuti, J in. whorls 5 or 6, spire short, umbilicus large, 



inner lip white. 



376. affinis, % in. spire short, umbilicus covered by a pad. 



