GENERA AND SPECIES. I* 1 



52. triangularis, Jin. x Jin. smooth, or with indistinct striations, acutely 

 triangular. 



small, and markedly triangular ; and truncata, which has the front margin nearly straight. 

 Of 51 there are three varieties globosa, which is fairly circular, with regular ribs, 

 striata, which is closely ribbed, and nana, which is smaller, and occasionally smooth. 



Avicula. (AVICULID&.) Plate iii. 



30. himndo, if x 3 in. shell elliptical and winged, upper valve 

 the larger. 



Axinus. (LUCINID&.) Plate vii. 



66. flexuosus, ^ in. x in. white, ligament visible outside. 



67. croulinensis, J in. x ^ in. white, ligament not visible outside. 



68. ferruginosus.^in. x Jin. reddish brown. 



Of 66 there is a variety f>olyona. which has a few longitudinal ridges. 



Balea. (PUPIDJE.) Plate xx. 

 303. perversa, | in. left handed, with a shining top whorl. 



There is a variety of this viridula which is greenish white, the typical colour being 

 yellowish brown. 



Barleeia. (RISSOID&.) Plate xxiv. 



425. rubra, f in. whorls, with a dark band, 5^, gradually 



enlarging, operculum dark red. 



The general colour is dark red or tawny, but there is a variety unifasciata which is 

 whitish, and there is another /0///Vfo which is pinkish white. 



Bithynia. (HYDROBIID&.) Plate xxiv. 



430. leachii, \ in. whorls 5, mouth nearly round. 



431. tentaculata, J in. whorls 6, mouth oval, angular above. 



Of 430 there is only one variety <?/<?vzte -which is smaller, with a longer spire. 

 Of the varieties of 431 ventricosa. is white with swollen whorls, decollata. has lost if- 

 upper whorls, and exccmata has rounded whorls and a deep suture. 



Buccinopsis. (BUCCINIDJE.} Plate xxvii. 

 519. dalei, ij in. colour ivory white. 



Variety eburnea shell thinner with the spire longer. 



Buccimim. (BUCCINIDjE.) Plate xxvii. 



517. undatum, 3^ in. outer lip sinuated deeply, inner lip broad. 



518. humphreysianum, if in. outer lip sinuated slightly or not at all, 



inner lip imperceptible. 



Of Buccinum there are many vaiieties, depending on the kind of ground on which the 

 animal lives, and many of them are as worthy of a name of their own as those to which 

 names have been given. Some are stout, some slender, some smoother, some smaller, some 

 more fully coloured, and, of course, there is the usual albino. The monstrosities are inter- 

 esting ; one has ridges on the upper part of each whorl, another has the body whorl com- 

 pressed and lengthened, so as to give the shell the shape of a volute, one has a long spire, and 

 some have been found with two or even three opercula. 



