Any Idea what types of Cars these are and year of manufacture?

Hello all



Following on from a thread misplaced in another section:





I was hoping to find out the makes of these cars in the attached photo. Sorry for the quality of the photo its the only one I have. Its the daphnia collection in the foreground that I am trying to put a year/era to.



The photo is from a later edition of a book published in 1966 Exotic Aquarium Fishes, the original edition was published in 1930's. I am not aware if the photo was in the original edition of the book?



The author was Dr. W. Innes from Philadelphia, I assume thats in the region where the photo was taken.



Any identification on any of these motors would be very much appreciated, that would lead to an approximate year of the photo



Thanks in advance



Dave