"....with such Leaders, Sariputra, in the eastern
direction the Buddhas, World Honored Ones,
comparable to Ganges River sand..."

    This continuer the list in section 10 of
the Buddhas in the East.  Evampramukhah  comes
after naming the most important Buddhas of that
direction, and it is a possessive adjective
compound agreeing with the subject(of the main
verb  yet to come): buddha (buddhas before
external sandhi).   It is composed of the noun
mudha "mouth/face/door," hence "head/top/chief,"
which combines with the prefix pra "very" to
make  the  adjective here  used as a substantive
meaning "chief/leader(s)" as final member of
the compound which has the indeclinable evam
"such/thus" as its first element--used in the
same way as in evamrupaih of the refrain to
sections 3-7 and 8, that is, as an adjective
modifying the second member:  "such leaders."
"With" is the translation of the possessive
idea inherent in such compounds:  the Buddhas
have such Buddhas as previously named at their
head.  The noun bhagavantah (bhagavantas) is in
apposition to buddhah, all three words being in
the nominative plural masculine.  Note that
the possessive suffix -vant terminates  this
noun, which therefore has -van (long a in the
nominative singular masculine) and -vantas as
the nominative olural masculine.  Participles
in  -ant, by constrast,  have short a in the first
case and lack n in the second.

     Purvasyam is  locative singular feminine of
adjective  purva "before/in front/east'' (uses
the  promominal  declension  when  stating  relative
location). It agrees with the feminine noun dib
"direction,"  from the root /dis "to point."

     Another possessive adjective compound in
agreement with buddhah is ganganadivaluhopama(h)
which is composed of four nouns: ganga(fem.)
the Ganges, nadi (fem.) "river," valuka (fem.)
"sand," and upama (fem.) "comparison/simile."
Even though the members of the compound are all
feminine nouns, the possessive adjective itself
is masculine,  for it modifies the masculine
noun buddhah and means Buddhas "possessing"(or)
"with as their comparison sand of the Ganges
River," that is, equal in number to the amount
of grains of sand in the Ganges River, noted
for its extremely fine and so extremely numerous
grains of sand.