prevented much trouble for students in future 

 by making the changes now demanded by 

 the law of priority. Even if he preferred to 

 adopt the other course in the body of the list, a 

 table might hâve been inserted in the appendix 

 showing the earliest names of groups for which 

 he had selected the best known désignation, 

 but even this seems to hâve been impracticable 

 on account of the undue length of the appendix. 



Without attempting to give such a table hère, 

 it will suffice to illustrate this point by men- 

 tioning 50 gênera and subgenera which hâve 

 not been corrected in the appendix. It should 

 be explained, however, that thèse do not by 

 any means include ail the names which rest on 

 an unstable basis. Full références are added, as 

 some of the gênera are not given in the catalogue, 

 although the majority of them are mentioned in 

 synonymy with merely authorities and dates. 



Page 4. For Siamanga, 1843 — substitute Sym- 

 phalangus Gloger, Hand- u. Hilfsb. Natur- 

 gesch,, I., p. 34, 1841. 



P. 44. For Brachyurus* 1823 — Oacajao Les- 

 son, Species des Mamm., pp. 181-188, 1840. 



P. 44. For subgenus Brachyurus Trouessart — 

 Cothurus nom. nov. Type Brachyurus calvus 

 Geoff. 



P. 46. For Chrysothrix, 1835— Saimiri Voigt, 

 Cuvier's Thierreich, I., p. 95, 1831. 



* Trouessart's Brachyurus contains two subgenera : 

 A, Ouakaria Gray, 1849 and B, Brachyurus. Since 

 Brachyurus Spix, 1823, is preoccupied by Brachyurus 

 Fischer, 1813, a group of field mice, the genus be- 

 oomes Cacq/ao Lesson, 1840, and subgenus A, Ouakaria 

 also beoomes Cacajao botli being based on Simia me- 

 lanocephala. Subgenus B, Brachyurus including the 

 redfaced species, if really worthy of séparation, ap- 

 parently requires a new name and may be called 

 Cothurus (docked tail). Ouakaria is not availablefor 

 this group as it bas already been restricted to the 

 blackheaded forms and Cercopiochus Gloger, 1841, 

 based on the uakaris in gênerai, must be restricted 

 to the same group since it was proposed before any of 

 the redfaced species had been described. 



