LITTORINA. 365 



at least two- thirds, and in the male not much more than one- 

 half of the spire : suture more or less deep, and always distinct : 

 mouth equal to about one-third of the lower portion of the 

 shell in females, but proportionally much smaller in males, 

 angulated and slightly channelled above, and considerably ex- 

 panded as well as angulated below: outer lip thin, a little 

 reflected, incurved towards the pillar: inner lip united with 

 the outer lip, and forming a thin glaze on the upper part of 

 the mouth : pillar short, but thick and very broad, especially 

 at the base ; it shelves inwards, and is white or light-coloured : 

 inside of a darker hue in coloured specimens : operculum horn- 

 colour, having four or five volutions, which are crossed by 

 curved and rather numerous striae in the line of growth ; the 

 under side has an irregular boss in the centre of the spire, 

 but no rim as in the last species. L. 0-65. B. 0-5. 



Var. 1. saxatilis. Stunted, nearly globular, usually smooth 

 or finely ribbed ; colour greyish with a white base. L. saxatilis, 

 Johnston, in Proc. Berw. Nat. Club, i. p. 268 ; F. & H. iii. p. 43, 

 pi. Ixxxvi. f. 4, 5. 



Var. 2. sulcata. Bibs flattened ; colour yellow, with pur- 

 plish-brown furrows. Turbo sulcatus, Leach, Syn. Moll. G. B. 

 p. 187, tab. ix. f. 6. 



Yar. 3. jugosa. Smaller than usual, having strong and 

 sharp spiral ridges, which are variable in number, and some- 

 times alternately larger and smaller. T.jugosus, Mont. Test. 

 Brit. pt. ii. p. 586, tab. xx. f. 2. 



Var. 4. patula. Ear-shaped and expanded, thinner ; spire 

 not prominent, placed somewhat obliquely ; mouth wide. L. 

 patella, Jeffreys (erroneously), Thorpe's Brit. Mar. Conch. 

 p. 259 ; F. & H. iii. p. 36, pi. Ixxxv. f. 6-10, and (animal) 

 pi. G G. f. 2. 



Var. 5. glohosa. Larger, globular,, thick, and nearly smooth. 



Var. 6. tenehrosa. Smaller, thinner, smoother, more tur- 

 reted, and having a deeper suture, dusky and often tessellated 

 or chequered. T. tenehrosus, Mont. Test. Brit. pt. ii. p. 303, 

 tab. XX. f. 4. L. tenehrosa, F. & H. iii. p. 39, pi. Ixxxiv. f. 11, 

 12, and ixxxv. f. 1-5. 



Var. 7. similis. Besembling the last variety in size and 

 shape, but more distinctly ribbed. 



Var. 8. Icevis. Oval, solid, and smooth. 



