11 



which prove to be synonyms, 289 species provided with shells, con- 



sisthig of — 



Acejihala lamellibranchiata 124 



Acephala palliobrancliiata 5 



Pteropoda 3 



Gasteropoda prosobranchiata 136 



Gasteropoda opisthobranchiata 21 



Of these the following are found in North America, being taken prin- 

 cipally from Dr. Gould's catalogue of the MoUusca of Massachusetts : — 



Acephala lamelli- Leda pygmoea 



BRANCHIATA. Peten Islandicus 



Anoniia aculeata 



Teredo navalis 

 Pbolas crispata 

 Saxicava arctica 



„ rugosa 

 My a arenaiia 



„ truncata 

 Panopoea Non rgiea 

 Solen ensis 

 TeUina proxima 

 Cypiina Islandica 

 Lucina borealis 



„ flexuosa 

 Turtonia minuta 

 Astarte sulcata 

 Mytilus edulis 

 Modiola modiolus 

 CreneUa discors 



,, decussata 



,, nigra 

 Nucula tenuis 

 Leda caudata 



Acephala pallio- 

 beanchiata. 



Hippothyris psittacea 

 Terebratula caput .ser- 

 pen tis 



Gasteeopoda proso- 

 biianchiata. 



Chiton albus 



,, asellus 



,, mannoreus 



,, ruber 



„ cinereus 

 Acmoea testudinalis 

 PropUidium ancyloide ? 

 Puncturella noaobina 

 Trochus (Margarita) c-ine- 

 reus 



,, „ undulatus 



Trochus (Margarita) he- 



licinus 

 Littorina rudis 



„ tenebrosa 



Lacuna vincta 



,, puteolus 

 Scalaria Greenlandica 

 Natica clausa 



„ pusUla 



,, helicoides 

 Velutina Icevigata 

 Lamellaria perspicua 

 Trichoti'opis borealis 

 Admeta crispa 

 Pui-pura lapillus 

 Buccinurn undatum 

 Fusus antiquus 



,, Islandicus 

 Trojihon clathratuiii 



„ harpulariuui 

 Mangelia Trevilliana 



,, turricula 



,, rnfa 



Being in proportion to the Scandinavian species — 



AceijhaJa lamellibranchiata 24 in 124, or 1!) per cenl. 



Acephala palliubranchiata 2 ,, 5, ,, 4(» ,, 



Pteropoda — 3, — 



Gasteropodo prosobrancliiata 32 ,, 130, ,, 24 „ 



Gasteropoda opisthobranchiata — 21, — 



Total of testaceous mollusca, common to Western Scandinavia and 

 North America, 58 in 289, or 20 per cent, of the former. 

 The Scandinavian specios found in the British seas are — 



ACF,PUAI>A LAMEI.U- 

 BBANCHIATA. 



Teredo navalis 



Korvngica 



Xylophaga dorsiilis 

 I'iiolas dactylus 

 ,, crispata 

 ,, Candida 



Saxicava arctica 

 „ rugosa 

 Mya arenaria 

 „ truncata 



