From Destinypedia, the Destiny wiki
Regulus is a class of jumpships. It has characteristic angular engines and several elongated antennae attached to the front. These ships were built to be speedy and nimble, used mostly for short travels.
Two popular variants of Regulus ships are Cloud Errant and High Water. The subtypes are often marked by a double number and letter(s), like 22a, 77 or NS44. Future War Cult seems to prefer this class of ships, as the faction-themed jumpships rewarded from Lakshmi-2 in Destiny are all Reguluses.
Known Regulus-class ships