llie Xoinenchitiire of the. Rheas of South America. 273 



DlTRI.ENA, gen, nov. 



Sternal cavity formed laterally by the mesosterniim and 

 posteriorly by the metasternuin. Lateral portions of the 

 mesosterniim moderately elongate. Antennal pores in a 

 fossa at the lower anterior angles of the joints. Front of 

 the head rather broad, nearly parallel-sided, not constricted 

 at the insertion of the antennae, the eyes scarcely oblique. 

 Scutellum small, transversely oval. Epipleural lobe of the 

 elytra considerably arched, so that it covers one-third of the 

 metasternal epipleuron. Antennae inserted very near the 

 eyes, as in Cinijra, the cavity very small and without any 

 distinct carina above it. Basal joint of the posterior tarsi 

 longer than the second joint, but not so long as the second 

 and third together. Thorax evenly convex, slightly trans- 

 verse, sides nearly parallel, the base with a small central 

 fovea. Elytra subparallel for some distance, and then 

 gradually narrowed to the apex (each armed witli three small 

 acute spines), striate-punctate, costate posteriorly. 



I think there can be no doubt that this genus should bs 

 placed next to Cinyra, from which it differs by its more 

 parallel form, shorter tarsi, and in having three spines at the 

 apex of each elytron. The tibiaj are rather stout, and the 

 middle as well as the anterior ones are slightly curved 

 inwards and tiuely serrate ou the inner side. 



XXXV. — The Nomenclature of the Rheas of South America. 

 By Lord Brabourne, F.Z.S., M.B.O.U., and C. Chubb, 

 F^Z.S., M.B.O.U., Zoological Department, British 

 Museum. 



On going into this question we find that Linnseus founded 

 his Struthio americanus (^ = Rhea americana) ou " Nhandu- 

 guacu brasiliensibus " of Marcgrave, and his name is 

 applicable to the bird known as Rhea macrorhyncha, Sclater, 

 P. Z. S. 1860, p. 207 ; consequently Rhea americana of 

 authors (nee Linn.) requires a new name, for which we 

 propose 



Rhea rothschildi. 



Adult male. Crown of head, lower hind-neck, middle of the 

 mantle, lower fore-ueck, and sides of the upper breast black; 

 sides of the crown, upper hind-neck, and upper fore-neck 



Ann. c£- Mag. N. Hist. Ser. 8. Vol. viii. 18 



