THE NAUTILUS. 77 



3. Cockerell, T. D. A. " Notes on Two Californian Nudi- 



branchs." Jour. MalacoL, Vol. viii, No. 4, Dec., 1901. 



4. Cockerell, T. D. A. and Eliot, C. "Notes on a Collection 



of Californian Nudibranchs. " Jour. MalacoL, xii, Pt. 

 3, 1905. 



5. Cooper, J. C. " Some new genera and species of California 



Mollusca." Proc. Cal. Ac. Nat. Sci., Vol. ii, 1862. 



6. Cooper, J. C. "New or Rare Mollusca Inhabiting the 



Cost of California," Pt. II. Proc. Cal. Ac. Nat. Sci., 

 Vol. iii, Pt. I, 1863. 



7.' Eschscholtz, F. " Zoologischer Atlas." Viertes Heft. 

 Berlin, 1831. 



8. O'Donoghue, C. H. " Nudibranchiate Mollusca from the 



Vancouver Island Region." Trans. Roy. Canadian 

 Inst., Vol. xiii, No. 1, 1951. 



9. O'Donoghue, C. H. "Notes on the Nudibranchiate Mol- 



lusca from the Vancouver Island Region," I. Colour 

 Variations. Trans. Roy. Canadian Inst. (in press). 



10. O'Donoghue, C. H. Ibid., III. Records of Species and 



Distribution. Trans. Roy. Canadian Inst. (in press). 



11. O'Donoghue, C. H. and O'Donoghue, E. Ibid:, II. The 



Spawn of Certain Species. Trans. Roy. Canadian Inst. 

 (in press). 



OBSERVATIONS UPON THE NOMENCLATURE OF SLUGS. 



BY H. A. PILSBRY. 



In preparing a faunal work the writer had occasion to men- 

 tion the types of Limax, Agriolimax and Arion. The attempt 

 disclosed various irregularities in the current use of these names. 



Before incorporating radical changes into a formal work, it 

 has seemed well to give the data here, in order that others in- 

 terested may criticize the inferences drawn, and possibly sug- 

 gest some mitigation of the unpleasant situation. While the 

 facts bearing on the names discussed have been carefully col- 

 lected, it is always possible that some name or publication has 

 been overlooked. 



