Question: The Sagittarius Dwarf Spheroidal Galaxy, a loop-shaped galaxy of the Milky Way, is which type of the three main classes of galaxy originally described by Edwin Hubble in "The Realm of the Nebulae?"
Sentence (from "Elliptical galaxy"): They are one of the three main classes of galaxy originally described by Edwin Hubble in his 1936 work "The Realm of the Nebulae", along with spiral and lenticular galaxies.
Relevant evidence: Yes