were given American-themed names following established patterns, e.g. the Martin Baltimore, Consolidated Catalina. The American services, with the exception of the U.S. Navy, were not generally in the habit of giving aircraft names, and many British-chosen names would later be adopted; e.g. the North American P-51 Mustang began life as the North American Mustang Mk.I with the RAF. U.S. Navy names, conversely, were being increasingly adopted by the Fleet Air Arm as 1942 and 1943 progressed, as in the case of the Grumman F4F Wildcat shedding its alternative Fleet Air Arm "Martlet" name in favour of "Wildcat", the original American naval name. Naval versions of aircraft not originally ordered for the Fleet Air Arm were given the prefix "Sea" such as with the Hawker Sea Hurricane and de Havilland Sea Venom while Seafire for the navalised Supermarine Spitfire was a contraction of "Sea Spitfire". Sometimes the naval version entered service without a corresponding land-based type doing so, as with the Hawker Sea Fury and de Havilland Sea Vixen. Naval aircraft ordered as such had names with a nautical theme – e.g. Supermarine Walrus, Blackburn Roc, Fairey Gannet. Torpedo bombers were given 'fish' names, e.g., Blackburn Shark, Fairey Swordfish, Fairey Barracuda. Mythological names, particularly with an association with water were common, such as Blackburn Iris – named for the goddess of sea and sky, and Nimrod the mighty hunter, used for the Hawker Siddeley Nimrod and Hawker Nimrod. Nimrod aside, many naval fighters were named for birds – such as the Fairey Flycatcher, Fairey Fulmar, Blackburn Skua and, before the aforementioned adoption of the U.S. Navy's existing names for Fleet Air Arm aircraft of American origin, Grumman Martlet (the martlet being a heraldic bird) for the F4F fighter. Training aircraft were given names related to academic institutions – Airspeed Oxford, North American Harvard, Boulton Paul Balliol, Fairchild Cornell. As with other American aircraft purchased, appropriate US names were used – the Harvard and Cornell universities. Alternative names for teachers were also used – De Havilland Dominie, Percival Provost, Miles Magister, Percival Proctor. Aircraft built for one role such as the Avro Anson or Armstrong Whitworth Albemarle but converted to other roles rarely changed their names. However significant changes in a design might result in a name change – the Avro Manchester was renamed Avro Lancaster, which was in turn renamed Avro Lincoln (initially Lancaster Mark IV) as the design was improved,