254 THK IVi: ACK IN CANADA. 



Acirsa Etchrichlii. Hollyoll. 



FoBsil — (i»cl)oc ; Hivirro-du-Loup ; Montreal; iiioHt almiitlant iit 

 RivuTC-du-Loup. (I'lato VI., Fig. 7.) 



Recent— Murray Hay ; Little Metis ; (Jrcenland ; nUu Ka8ti)urt 

 (Vcrrill). 



This shell was named in former papers }fiiiislho (ilhuhi, the eroded 

 specimens found being referred to that species. It has, however, been 

 correctly described by Dr. Heck in Lyell's paper on Heauport, and 

 named Sett/itriu hore<i/in. It is not this species of (iould, however. 



Tricliolropis hoifulin. IJrod. and Sow. 



Fossil — Montreal ; Riviero-du-Loup ; Ciiaudicre Station ; Labra- 

 dor, Ac. Very abundant at Montreal. 



Recent — Labrador; Little Metis; Murray Hay; (iaspc ; Arctic 

 seas ; and as far south as Massachusetts ; Alaska (Dall). 



TrichotrojtiH ttniicd ? Middendorfl". 



Fossil — Montreal. Very rare. (I'lateVL, Fig. 8.) 



A single imperfect specimen represents tliis species, which is recent 



at Alaska (Dall) and Hehring's Straits. The identification is perhaj-s 



doubtful. 



The figure given by Reeve of T. Ktnstn of Phillippi from Spitz- 



bergen, resembles our shell, except in the small number of rev( Iving 



bands. 



Admele tiridida. Fabricius. 



Fossil — Montreal ; Chaudirre Station. 



Recent — Labrador (Packard); Little Metis; Rivirre-du-Loup ; 

 Murray l?ay ; (Jaspe (Whiteav(!s) ; also Greenland, Labrador and 

 Hritish Columbia. It is the Tritonium tiridulum of Fabricius, and is 

 a rare shell in the Canadian I'leistocenc, and in the Gulf of St. 

 Lawrence. 



Aporrhais occidenUdis. Beck. 



Fossil — Labrador (Hayfield) ; also Packard. 

 Recent — Little Metis ; (Jaspe ; Labrador to Massachusetts. 

 It is remarkable that this species, which is found living from 

 Labrador to Cape Cod, is so rare in the Pleistocene. 



Ptychatractus Ugatus (= Fasciolnria lignta, Mighels). 



Fossil — Montreal ; very rare. 



Recent— Murray liay ; Mingau (Foote) ; Gaspe (Whiteaves) ; Nova 

 Scotia (Willis) ; rare in all these localities. 



