sentences:  A second, enclosed turret was fitted in the dorsal position, also armed with a 7.7 mm (.303 in) Lewis gun, manned by the gunner/radio operator, who was also provided with an R.A.350 transmitter and an A.R.4 receiver.The aircraft was not fitted with an intercom, but the two pilots could communicate with the nose position using a "pneumatic message" system in which messages were passed through a tube.The forward machine gun had 564 rounds of ammunition in 12 magazines, while the aft machine gun had 470 in 10 magazines.