Edmund Ludlow (1835-1904) is the older dude sitting down. My grandfather (Christopher - 1877-1959) and his brother (Edmund James - 1866 -1945 - known as Ted - so as not to be confused with his father Edmund. The others are Sophia Jane (1872-1918), Amy Jane (1865-1950), Harriet Hannah (1869-1950)...
This is Ludlow Ship and Insurance Brokers - Commission Agents and Vice Consul for the Netherlands. William Bollom Ludlow (1835-1904) is on the left - so the picture is pre-1904.