  Low-albedo, hydrated objects dominate the list of the largest asteroids.
These objects have varied spectral shapes in the 3-$\mu$m region, where
diagnostic absorptions due to volatile species are found. Dawn's visit to Ceres
has extended the view shaped by ground-based observing, and shown that world to
be a complex one, potentially still experiencing geological activity. We
present 33 observations from 2.2-4.0 $\mu$m of eight large (greater than 200 km
diameter) asteroids from the C spectral complex, with spectra inconsistent with
the hydrated minerals we see in meteorites. We characterize their absorption
band characteristics via polynomial and Gaussian fits to test their spectral
similarity to Ceres, the asteroid 24 Themis (thought to be covered in ice
frost), and the asteroid 51 Nemausa (spectrally similar to the CM meteorites).
We confirm most of the observations are inconsistent with what is seen in
meteorites and require additional absorbers. We find clusters in band centers
that correspond to Ceres- and Themis-like spectra, but no hiatus in the
distribution suitable for use to simply distinguish between them. We also find
a range of band centers in the spectra that approaches what is seen on Comet
67P. Finally, variation is seen between observations for some objects, with the
variation on 324 Bamberga consistent with hemispheric-level difference in
composition. Given the ubiquity of objects with 3-$\mu$m spectra unlike what we
see in meteorites, and the similarity of those spectra to the published spectra
of Ceres and Themis, these objects appear much more to be archetypes than
outliers.
