144 THE NAUTILUS. 



considerable divergence among the species. Other biologic 

 notes and information on the ecologic relations of Cerions are 

 given. 59 plates fully illustrate the material. 



Dr. Bartsch's experiments clearly have important bearings 

 upon systematic zoology as well as upon the doctrine of evolu- 

 tion generally. H. A. P. 



MOLLUSCA OF THE CROCKER LAND EXPEDITION TO NORTHWEST 



GREENLAND AND GRINNELL LAND. By Frank C. Baker (Bull. 

 Amer. Mus. Nat. Hist., Vol. 41, pp. 479-517, pis. 25-27, Dec., 

 1919). An interesting review of some of the arctic mollusks, 

 especially of the Buccinidae of which Buccinum tanquaryi and 

 B. ekblawi are described as new. 



FRESH-WATER MOLLUSCA FROM COLORADO AND ALBERTA. By 

 Frank C. Baker (Bull. Amer. Mus. Nat. History, Vol. 41, pp. 

 527-539, Dec., 1919). Planorbis similaris, Physa smithi and 

 Galba alberta are described and figured as new. 



NEW SHELLS FROM THE NORTHWEST COAST. By William H. 

 Dall (Proc. Biol. Soc. Wash., Vol. 32, pp. 239-252, Dec., 

 1919). Ten new species and varieties and a new genus Pantel- 

 laria (type Megerlia monstruosa Scacchi) are described. 



LOCOMOTION IN TWO SPECIES OF THE GASTROPOD GENUS ALEC- 

 TRION WITH OBSERVATIONS ON THE BEHAVIOR OF PEDAL CILIA. 

 By Manton Copeland (Biol. Bull., Vol. 37, pp. 126-138, 1919). 



THE CENTRAL NERVOUS SYSTEM OF NUCULA AND MALLETIA. 

 By W. A. Hilton (Jour. Ent. and Zool., Vol. 11, pp. 75-78, 

 1919). 



NEW SPECIES OF MOLLUSCA FROM VARIOUS DREDGINGS TAKEN 

 OF THE COAST OF NEW ZEALAND, THE SNARES ISLANDS AND THE 

 BOUNTY ISLANDS. By Miss M. K. Mestayer (Trans, and Proc. 

 N. Zealand Inst., 1919, Vol. 51, pp. 130-135, pi. 8). Liotia 

 suturi, Orbestella hinenioa, Crossea cuvieriana, Leucosyrinx thomsoni, 

 L. cuvierensis and Vepecula cooperi are described as new. 



