  Recent numerical simulations of the fragmentation of primordial molecular
clouds in hierarchical cosmogonies have suggested that the very first stars
(the so-called Population III) may have been rather massive. Here we point out
that a numerous population of massive black holes (MBHs) -- with masses
intermediate between those of stellar and supermassive holes -- may be the
endproduct of such an episode of pregalactic star formation. If only one MBH
with m > 150 msun formed in each of the `minihalos' collapsing at z=20 from
3-sigma fluctuations, then the mass density of Pop III MBHs would be comparable
to that of the supermassive variety observed in the nuclei of galaxies. Since
they form in high-sigma rare density peaks, relic MBHs are predicted to cluster
in the bulges of present-day galaxies as they become incorporated through a
series of mergers into larger and larger systems. Dynamical friction would
cause more than 50 (m/150 msun)^{1/2} such objects to sink towards the center.
The presence of a small cluster of MBHs in galaxy nuclei may have several
interesting consequences associated with tidal captures of ordinary stars
(likely followed by disruption), MBH capture by the central supermassive black
hole, gravitational wave radiation from such coalescences. Accreting
pregalactic MBHs may be detectable as ultra-luminous, off-nuclear X-ray
sources.
