144 THK NAUTILUS. 



position oi tlie jjirgei- groups. Tliis feature is very clearly shown in 

 an excellent " Manual of Zoology," by Richard Hertwig, recently 

 translated by Prof. J. 8. Kingsley. " This Ameiican edition is not 

 an exact translation. Witii tlie consent of the author, the whole text 

 has been edited and modified in [)laces to accord with American 

 usage," 



The MoJiusca (Phylum VI) are divided into five classes, of which 

 the Aitrpfiineiirn, including two subclasses, Placophora (Chitons) and 

 Aplacophora are considered the most primitive. Class II comprises 

 Acephald or Pelecypoda, in which the views of Pelseneer are closely 

 followed. Tiie order Protochonchice includes most of the families 

 grouped by Dr. Dall under Pn'o7iodesniacea,ex(n'\)t the iV^a<V/(/a?, which^ 

 with the remainder of the families, are placed in the order Hetero- 

 conchise. The NuculidsefiVkt considered the most primitive, while the 

 more highly specializ*id families, like the Teredidce and Gastrochse- 

 nidse, are placed at the other extreme. Scaphopoda (Class III) are 

 placed between {\\q Pelecypoda and Gasteropoda; the latter being 

 divided into three orders: Prosobranchia, Opisthobranchia and iW- 

 monata. The Prosobranchs are divided into two suborders: Aspido- 

 branchia — of which the Docoglossd ( Lim[)ets) are the most primitive — 

 andthe Peciinibranchia. Heteropoda " in all details of gills, genitalia, 

 heart an<l nervous system are true Pectinibranchi, but from an ex- 

 clusively pelagic life have acquired peculiar modifications." The 

 Opisthobrajichia consists of three suborders : Tectibranchia, Ptero- 

 poda — "pelagic forms which in most points of structure agree with 

 the TectihranchV — and Nudibranchia. Class V comprises the Cepha- 

 lopoda— C. W. J. 



The junior editor of the Nautilus has been appointed Cuiator of 

 the Boston Society of Natural History, Boston, Mass. This will be 

 his future address. 



Errata In the article " Notes on Pyramidula elrodi Pils." in 



the February Nautilus, McDonald Lake of the Mission Mountains 

 should be read instead of Post Lake. There are two McDonald 

 Lakes in Montana, and the autiiorities seem to think the same name 

 for two lakes within a hundred miles of each other must stand. — 

 M. J. Elrod. 



