342 LITTORINIDZ. 
size, resulting from the various complicated incidents attached 
to habitat. 
I omitted to observe that the Littorine are destitute of 
head- and neck-lappets, and that the operculigerous lobe is 
small, simple, and not co-extensive with its organ. 
L. rupis, Donovan. 
L. rudis, Brit. Moll. iii. p. 32, pl. 83. £. 1, 2,3, 5, 6, 7, & pl. 86. f. 1. 
L. patula, Jeffreys, Brit. Moll. ii. p. 36, pl. 85. f. 6-10; (animal) 
pl. G.G. f. 2: 
L. tenebrosa, Mont., Brit. Moll. iu. p. 39, pl. 84. f. 11,12, & pl. 85. 
Fel=o: 
L. saxatilis, Johnston, Brit. Moll. ui. p. 43, pl. 86. f. 4, 5. 
L. fabalis, Turton, Brit. Moll. iii. p. 49, pl. 86. f. 2, 3. 
L. palliata, Say, Brit. Moll. ii. p. 51, pl. 84. f. 8, 9, 10. 
L. zonaria, L. rudissima, L. jugosa, L. neglecta, Auct. 
This well-marked species has nearly the same organs as 
L. littorea; J have compared the nervous ganglions and other 
internal parts of both forms, without finding distinction. To 
enumerate the greater part of the other organs, in comparison 
with those of L. littorea, would be a repetition; I will only 
mention the essential specific distinction, which is, that im 
the females of this species the large bulky ovarium is usually 
filed with strings of testaceous pulli, that is, if examined 
at the season when, O! Alma Venus, they are “perculsz 
corda tuad vi,” the ovaries fill up the tumid antepenultimate 
volutions. The markings and colours of the animal have the 
same character as those of Littorina littorea, except that they 
are much less intense; but though closely allied, it is parti- 
cularly distinguished by the much higher littoral level of its 
habitat, the greater tumidity of the volutions, by the colour, 
and, above all, by the very different ovarium, its contents and 
mode of reproduction. It rarely exceeds an inch in length, 
and 3 of an inch in diameter. 
To describe the varieties enumerated above, which are the 
pseudo-species of authors, would be to say, that the organs of 
all, both internal and external, do not vary in the slightest 
degree in form; the only differences are modifications of 
colour, size, and in the strize, depending entirely on habitat. 
