formn (\p^ r«*«rr orthogonales, oil Ips surfaces dune 



. ,_ :. . _..! ..;. m^mefamilleadmettentlamdmerepr^- 



soiitalion8ph6riquede leurs lignt'S de 



rourbure; parM. Matirice Foucht. . 



<\\r \<* fon'lempnt de la GAonx^trit* pro- 



,..-liv..- n:ir \\ '/..'.nh.-n 



