*3759.87   O III*
Visible in O stars

*3819.61   He I*
Strongest in B stars with maximum
around B2

*3933.68   Ca II (K line)*
First visible around A0.
Progressively stronger A1 -> A9
K line = H line(blend) at ~F0
Strongest from G8-K2.

*3964.73   He I*
Visible in O6-B9, but strongest
around B0-B2

*3968.49   Ca II (H line)*
Appears blended with
       adjacent H epsilon until mid F
H line(blend) = K line at ~F0
Strongest from G8-K2.

*3970.07   H I (H Epsilon)*
Hydrogen Balmer Series 
Reaches Maximum Strength at A0
Can be confused with adjacent Ca II H line,
      which is strong in cooler stars.

*4026.19   He I*
Strongest in B stars with maximum
around B2

*4030.76   Mn I*
Compare to 4130 Si II line
for discrimination in F stars

*4045.82   Fe I*
Visible in F0 and cooler stars.
Strongest in K2-K5

Comparison with H I 4101 line
gives an indication of spectral
type in G stars. They are about
equal at G8

*4068.00   C III*
Strongest in O stars between
O6 and O9

*4073.00   O II*
Visible in O9-B2

*4088.85   Si IV*
Strongest in O stars between
O6 and O9

*4097.33   N III*
Visible in B0-B2

*4100.04   He II*
Strongest in O stars

*4101.75   H I (H Delta)*
Hydrogen Balmer Series
Reaches Maximum Strength at A0

*4120.82   He I*
Strongest in B stars with maximum
around B2

Ratio of this line to nearby Si II 4130
provides fine discrimination in this 
range. Si just visible at B3

*4130.89   Si II*
Visible from B2 to A5

Ratio of this line to nearby He I 4121
provides fine discrimination in this 
range. Just visible at B3.

Ratio of this line to nearby He 4144 
provides fine discrimination in  this
range, with maximum of the Si line
at B5-B8

Ratio of this line to Mn 4030 line provides
discrimination in the F stars.

*4143.76   He I*
Strongest in B stars with maximum
around B2

Ratio of this line to nearby Si  4130. 
provides fine discrimination in  this
range, with maximum of the Si line
at B5-B8

*4143.88   Fe I*
Appear in F0 and cooler stars
Strongest in K2-K5

Ratio of this line to H I delta 
at 4101 is a discriminant  They are
about equal at G8

*4226.74   Ca I*
First a visible around F0.  Strenghtens
to cooler K and M stars, where it is
prominent.

In F stars, where the H I (Balmer) lines do not 
change in strength much, Ca I helps 
discriminate.  Commpare to nearby 
H I 4340 line; Ca I strengthens as one goes
from F0 to F9

In G stars, relative strength of this line to
the H 4101 line can be used to determine
precise spectral type

*4267.      C II*
Visible from B0-B8, but strongest
at B4

*4300.00   CH & Metals (G Band)*
First visible around F5 in main sequence 
stars, and G0 in supergiants.  It becomes 
prominent in cooler stars, G, K, M.

*4317.14   O II*
Visible in O9-B2

*4340.48   H I (H Gamma)*
Hydrogen Balmer Series
Reaches Maximum Strength at A0

*4383.56   Fe I*
Strongest in K2-K5

*4387.93   He I*
Strongest in B stars with maximum
around B2

*4471.48   He I*
Strongest in B stars with maximum
around B2
HeII  4541/HeI 4471 strength is a useful
indicator of type between O3-O9


*4471.68   He I*
Strongest in B stars with maximum
around B2

Ratio of this line to nearby Mg II 4481
provides discrimination around B8-B9

*4481.20   Mg II*
Evident in B2-A5; Strongest at A1.

Ratio of this line to nearby He I 4471
provides discrimination around B8-B9

*4541.00   He II*
Strongest in O stars

*4552.62   Si III*
Strongest in types B0-B2
