62 THE NAUTILUS. 



knowledge of the attractive shells of California. To these little 

 books we may fairly ascribe much of the wide-spread interest which 

 is to-day found among Californians and which by the cooperation of 

 amateurs with specialists, has immensely increased our knowledge of 

 the Pacific Coast fauna. 



The last of these manuals was published only shortly before his 

 death. Professor Keep was one of the founders of the Chautauqua 

 Assembly which meets at Pacific Grove, and frequently lectured to 

 its classes on his favorite subjec<^. He was also one of the most 

 earnest supporters of the Museum and Library at Pacific Grove. 



Modest, courteous, indefatigable and enthusiastic, he was primarily 

 a teacher and organizer ; beloved by his classes and appreciated by 

 those reached through his books and so led to the study of nature. 

 In his unassuming way he has done a good work and found his re- 

 ward in doing it. He leaves a widow, son and daughter to mourn 

 his loss. 



ADDITIONAL NOTES ON THE LOCOMOTIVE DISK OF STYLCMMATOPHOEA. 



BY V. STERKI. 



During the last years some additional observations on this subject 

 were made. Nearly all of the species mentioned in the former 

 article have been seen again and the data were verified, and some 

 others were examined. To repeat, there are marked differences in 

 this respect, between species, genera and groups apparently or really 

 closely related, especially among the Zonitidas, and these features 

 have probably much significance in classification, in connection with 

 the formation of the lateral (marginal) longitudinal groove or grooves, 

 on the upper surface of the foot (pedal grooves), and possibly the 

 presence or absence of the caudal mucus gland, as pointed out, e. g., 

 by Dr. Pilsbry.'* More observations and morphological and ana- 

 tomical examination are needed on the subject. 



ZonitidcB. 

 Omphalina fuliginosa (Griff.). The median zone was seen (or 



iSee article in Thb Nautilus, XXII, p. 49, 1908. 



2 In the generic position of PaUdastra * * * with suggestions of a classifi- 

 cation of the American Zonitidse, The Nautilus, IX, p. 19. 



