Enlarging lenses with-and-without caps. The ones without the original rear caps or cases, have aftermarket caps (not shown) From Right to Left:

Rokkor CE with plastic case as rear cap (? front cap)
Behind a Schneider Betaveron with front push-on cap and rear hard plastic screw-on cap.
Schneider Componon S with plastic case as rear cap and original front push-on cap.
Front Omegaron with original Rodenstock special cap, it squeezes inside the opening.
Behind Komura with plastic case (? front cap)
EL-Nikkor with plastic case and original squeeze-to-release front cap
300mm Schneider Componon with original front cap (? rear cap)