. Gulf of Mexico on the south and California or the Paci 
468 A. FE. Verrill on the Mollusca of Europe and N. America. 
tra solidissima, Kellia planulata, Macoma fusca, Tellina tenera, 
Astarte castanea, A. quadrans, A. sulcata, Nucula proxima, Yoldia 
limatula, Mytilus edulis, Elysia chlorotica, Crucibulum striatum, 
Littorina rudis, L. tenebrosa, L. palliata, Lunatia heros, L. trisert- 
ata, Nassa trivittata, Melampus bidentatus, Alexia myosotis. 
any others, not named in the above lists, are not limited by 
Cape Cod ; but as they belong properly to the northern division, 
they are here omitted. 
As an offset of thesé numerous instances in which he has 
unduly exaggerated our northern fauna, we find not one un- 
doubted instance of an error on the other side, among the 
marine shells. 
The distribution indicated for our land and freshwater shells 
is even more erroneous. It is sufficiently evident that Cape 
Cod is in no sense a proper boundary between the northern and 
southern fluviatile and terrestrial species; but, disregarding 
this, there are no reasons whatever for most of the special indi- 
cations that he gives. 
western parts of the United States, some even extending to the 
southern parts. Unio complanatus, U. nasutus, Margarivane 
cariosus, U. ochraceus, Margaritana undulata, M. marginata, An- 
odon fluviatilis, and A. undulatus are put down as southern. It 
iy : 
All of the eighty-one species of Helix, Hyalina, Macrocyelis, 
Limax, Pupa, Vertigo, Succinea, Arion, Zonites, Tebennophorus, 
ipa fallax, Limneea catascopium, and Physa ancillaria. 
_ Species are — widely distributed over North America, east, 
west, north, and south, many of them being limited only by the 
| con the 
West. Nor is there any reason for the distinction made in the 
of 
