We present new size, line ratio, and velocity width measurements for six
strong emission-line galaxies in the galaxy cluster, Cl 0024+1654, at redshift
z~0.4. The velocity widths from Keck spectra are all narrow (30<sigma<120
km/s), with three profiles showing double peaks. Four galaxies have low masses
(M<10^{10} Mo). Whereas three galaxies were previously reported to be possible
AGNs, none exhibit AGN-like emission line ratios or velocity widths. Two or
three appear as very blue spirals with the remainder more akin to luminous H-II
galaxies undergoing a strong burst of star formation. We propose that after the
burst subsides, these galaxies will transform into quiescent dwarfs, and are
thus progenitors of some cluster spheroidals (We adopt the nomenclature
suggested by Kormendy & Bender (1994), i.e., low-density, dwarf ellipsoidal
galaxies like NGC 205 are called `spheroidals' instead of `dwarf ellipticals')
seen today.Comment: 14 pages + 2 figures + 1 table, LaTeX, Acc. for publ. in ApJL also
available at http://www.ucolick.org/~deep/papers/papers.htm