﻿A. E. Verrill on the Mollusca of Europe and N. America. 3 



Cod, actually belong properly to the region south of Cape Cod, 

 extending in most cases to the Carolina coasts or beyond, while 

 north of Cape Cod they are rare or local, viz. : — Cochlodesma 

 Leanum^ Macira lateralis^ Petricola, pholadiformis, P. dactyhis, 

 Oouldia mactracea^ Cyiherea convexa, Venus mercenaria^ V. no- 

 iata., Gemma gemma, Liocardium Mortoni, Area transversa, 

 Modiola plicatula, Pecten irradians, Ostrea Virginiana, Anomia 

 electrwa (not of Linn.), Diaphana dehilis, Cylichna oryza, Place- 

 hranchus caiulus, Crepidida fornicata, C. plana, G. convexa, G. 

 glauca, lanthina fragdis, BitUum Greenii, Odostomia hisuturalis, 

 0. seminuda, TiirhonUla interrupta, Pleurotoma bicarinaia, P. pli- 

 caia, Nassa obsoleta, Buccinum cinereum, Diacria trispinosa, Lo- 

 ligo Pealii. 



The following, to which a northern distribution is likewise 

 given, are also found far south of Cape Cod, and many of them 

 belong quite as much to the southern as to the northern division ; 

 and some of them are decidedly southern, extending even to the 

 Gulf of Mexico : — Teredo navnlis, T. megotara, T. cklorotica, Solen 

 ensis, Machcara costata. Pandora trilineata, Lyonsia hyalina, Mac- 

 tra solidissima, Kellia plamdata, Macoma fusca, Tellina tenera, 

 Astarte castanea, A. quadrans. A, sulcata, Nucula proxima, Yoldia 

 limatula, MytUus eduUs, Elysia cklorotica, Grucihulum striatum, 

 Littorina rudis, L. lenehrosa, L. palliata, Lunalia heros, L. triseri- 

 ata, Nassa trivittata, Melampus bidentatus. Alexia myosotis. 



Many 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 these 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, disregai'ding 

 this, there are no reasons whatever for most of the special indi- 

 cations that he gives. 



Thus he gives the northern distribution to all of the sixteen 

 species of Sphoe.rium and Pisidium ; but most of them n.re well 

 known to be widely distributed over the eastern, middle, and 

 western parts of the United States, some even extending to the 

 southern parts, JJnio comp)lanatus, U. nasutxs, Margaritana 

 arcuata, and Anodon implicatus are indicated as distributed 

 north of Cape Cod ; but all these are found over most of the 

 northern and middle states and some in the western, while the 

 last one is somewhat rare at the north. But Unio radiatus, U. 

 cariosus, TJ. ochraceus, Margaritana undulata, M. marginata, An- 



