SOTALIA GUIANENSIS. 17 



SOTALIA GUIANENSIS (Van Eeuetkn). 



Dclphiniisfjuiaiiciisis, Van Ben., Mem. Conruii. Acail. Koyalc Bolg., cull, iu 6" xvi 

 18G4, art. i>, 1 pi. ^ = , • , 



Sotalia guiancnsls, Gray, Cat. .Seals and Whak\«, Brit. Miis., ISGf), p. 401. 

 SOTALIA BRASILIENSIS E. Van Benedeu. 



Sotalia hnuilioisis, E. Van Ben.. Mem. Acad. Royalo Bdg , xli, 1S7."), art. ], 

 jds. 1 and 2. 



SOTALIA TALLICA (Gervais). 



Ddphinm pallidiis, Gervais, Castcliiau Exped. dans I'xVnidr. Sad, pt. vn, 



Zoologie, It^OC), p. 1)4, pi. xix, ligs. 1-2. 

 Sotalia inxUida, Van Ben. and Gervais. Osteog. des CY-tacd.s, IbSO, p. 51)."). 



SOTALIA TUCUXI (Gray). 



SlCHo tiicuxi, Gray, Ann. and Mag. Nat. Plist., "id ser., xviii, 185G, p. 158. 

 Solalia tuciiri, Flower, Proc. Zool. Soc. Loudon, 1883, p. 513. 



SOTALIA FLUVIATILIS (Gervais). 



Dcl2)hiiius Jlui-iatUis, Gervais, Ball. Soc. d'Agric. II6rault, xl, 18,')3, p. 148 {sine 



(Icscr.). 

 Sotalia fluviatilis, Van Ben. and Gervais, Ost<;og. des Cdtaci5s, 1880, p. 5%. 



Of these five nominal species, one, S. ouianensis, is from Cayenne; 

 tliree from the Amazon River, S. paUida^ iucuxi, and Jiuviaiilis ; and 

 one, 8. brasiUcmis, from the bay of Ixio de Janeiro. At least two skele- 

 tons of A', (juianensis are to be fonnd in the Enropean collections and 

 one of S. brasiUcnsis. The latter, however, is that of so yonng- an ani- 

 mal as to make comparisons of little value. The description of iS. 

 tucuxi was drawn from two skulls iu the British Museum. A skull of 

 ^'. fltiviatUis is said to be in the Paris jMusenm,* but is not figured by 

 Van Beuedeu and Gervais in the Osteograidiie.f These authors, how- 

 ever, figure and describe portions of a skeleton of >S'. pallida., also said 

 to be in the Paris Museum. 



Professor Flower justly remarks that the materials are not at present 

 sufficient for the proper determination of these species. Nevertheless, 

 several opinions have been advanced regarding them. M. Ed, Van 

 Beuedeu has brought forward characters which he views as distinguish- 

 ing *S'. hrasiUcnsis from S. guianensis. The authors of the Osteographie 

 apparently held the same view, and at the same time united S.JIuviatilis 

 to S. pallida. Gray believed that 8. tucuxi might also be identical 

 with 8. pallida^! while Professor Flower finds it difficult to distinguish 

 between these two species and 8. hrasiliensis. 



It is only between 8. (juianensis and 8. &ra6?7/e«6'/s that comparisons of 

 any moment have been made, and the value of these is unfortunately 



*Mcm. Acad. Belg., xli, 1875, art. 1, p. 4. 



t The references to the figures of So.taVia in lliis work are very coufnsiag. The legend 

 of platoxLi is as follows: " 1-5, S. gnyauensis. G-17, S. pallida," In the " explication 

 des planches," however, all the figures ou this plato are i)laccd under the heading of 

 S. giiijancnsi^i, while iu the text (p. 598) fig. 7 is referred to as S. Jlnviatilia, 

 1837S— Bull. 30 2 



