The Collaborative International Dictionary of English v.0.48:

Leptorhine \Lep"to*rhine\ (l[e^]p"t[-o]*r[imac]n or *r[i^]n), a.
   [Gr. lepto`s small + "ri`s, "rino`s, the nose.] (Anat.)
   Having the nose narrow; -- said especially of the skull.
   Opposed to platyrhine.
   [1913 Webster]

WordNet (r) 3.0 (2006):

leptorhine
    adj 1: having a long narrow nose [syn: leptorrhine,
           leptorhine, leptorrhinian, leptorrhinic] [ant:
           broadnosed, catarrhine, catarrhinian, platyrhine,
           platyrhinian, platyrrhine, platyrrhinian,
           platyrrhinic]