z < 0.063$. [@vdb2017] extended this investigation to lower masses, looking at 325 galaxy groups from the GAMA survey in 7 mass bins. For Coma, we apply our UDG criteria to the [@yagi2016] catalog finding ${\sim}200$ such objects. And similarly for Fornax, we apply our selection criteria to the [@munoz2015] catalog. This catalog, however, only covers the inner 350 kpc so we apply a geometrical correction by assuming the flat radial surface density profile they found for dwarfs applies to UDGs out to $R_{200} =
700~\mathrm{kpc}$ [@drinkwater2001] and estimate a total of ${\sim}30$ UDGs. Finally, we include the abundances of UDGs in Abell 168 and UDG 842 [@roman2017a] and three Hickson Compact Groups [@roman2017b].

In the Virgo cluster, [@impey1988] identify 27 large low surface brightness galaxies. Most have scale lengths $h \gtrsim 10\arcsec$ and central surface brightnesses in the $B$-band fainter than $\mu_{0,B} \approx
23~\mathrm{mag}~\mathrm{arcsec}^{-2}$. For $n=1$ Sérsic profiles, $\langle\mu\rangle_e = \mu_0 + 1.12$ and the effective radius is related to the scale length via $R_e = 1.678h$ [@graham2005], meaning they have $R_e \gtrsim 1.5$ kpc[^2] and $\langle\mu\rangle_{e,B} \gtrsim 24~\mathrm{mag}~\mathrm{arcsec}^{-2}$, satisfying the rough definition of a UDG. In their Figure 7b, we find a total of 37 galaxies that satisfy 