Chapter 60: On the distinction between stella, sidus, and

_astrum_.

1. _Stellae_, _sidera_, and _astra_ differ from one another. For _stella_ is any separate star. _Sidera_ are made of very many stars, as Hyades, Pleiades. _Astra_ are large stars as Orion, Bootes. But the writers confuse these names, putting _astra_ for _stella_ and _stella_ for _sidera_.[273]

[273] Isidore does not observe the distinctions he lays down
here. He does not seem to have known that Orion and Bootes were
constellations.