268 AMERICAN JOURNAL 



denticulate, posterior ; uncini distinct, similar, three on each side. 

 Formula, '-^ 



3(1— 2-2— 1)3 • 



Type Patella vulgata, Lin. Plate 15, fig. 23. 



Patella vulgata, Linne, Syst. Nat. Ed. 12, p. 1258. Forbes 

 and Hanley, Brit. Moll, ii, p. 421. Jeffreys, Brit. Conch, 

 iii, p. 236. 



Soft parts : foot slate colored, sides smooth, yellowish, some- 

 what dusky with a pale border; mantle yellowish, edge thick- 

 ened, furnished with tentacular filaments, varying in length and 

 corresponding in position to the ribs and strite of the shell, ex- 

 treme edge sometimes dusk-y ; branchial cordon uninterrupted, 

 laminae rather smaller in front of the head, of a pellucid yellow- 

 ish color ; head short, stout; tentacles moderate, pointed, yel- 

 lowish, darker at the tips ; muzzle indented below, bordered 

 with granulose papillte, especially below ; disk radiately striate ; 

 eyes small, on superior bases of the tentacles ; not raised above 

 the swollen base, which has a prominent tubercle on the inner 

 edge ; anal orifice on the right side at the junction of the man- 

 tle with the neck, prominent, inclined to the right, but not ob- 

 liquely truncate as in some species, orifice rounded, internally 

 papillose ; renal orifice on a small yellowish tubercle to the left 

 of the anal ; infra-anal papilla similar, inconspicuous, to the ex- 

 treme right. Formula, I! 



^ ' :i(>/_2-2~J^)3- 



Habitat. British and North European seas from the Loffoden 

 Isles to the Mediterranean. 



The minute anatomy of this species still stands in need of 

 much elucidation ; and, as one of the best known species of the 

 order, a synopsis of what is known and what is undetermined 

 will give a good idea of the extent of our knowledge of the 

 anatomy of the group. 



It does not speak well for English naturalists, that for infor- 

 mation in regard to one of the most common of their littoral 

 animals, many points of which have been matters of doubt for 

 many years, we should be obliged to turn to Russian and French 

 publications for the little that has been made known, except in 

 regard to the branchiaj. A few scattered and very short arti- 

 cles by Gray, Lankester, and Patterson, beside the work of Dr. 

 Williams, are about all that English works afford us ; while 

 Brandt, Fischer, Milne-Edwards, Lebert, Cuvier and others have 

 done far more, though much remains to be done. 



The branch itB have been thoroughly described by Dr. Williams 

 in the paper before referred to, though a careful dissection of 

 the gill of Acma!a is still a desideratum. In Patella vulgata 



