1861.] DR. p. L. SCLATER ON NEW AMERICAN BIRDS. 



127 



NEMATODA 



r crassicauda. 

 \ obtusa. 

 '' depressa. 



dispar. 



lineata. 



retusa. 



tribothrioides. 



vesicularis. 



EusTRONGVLUs papillosus. 



f acuticaudatus. 



Spiroptera 



ASCARIS 



Stuongylus 



ACANTHOCEPHALA. 



Trichocephalus .. 



"^ Trichosoma 



echinorhynchus. 



nodularis, 

 paradoxus, 

 spiculatus. 

 I, tubifex. 

 affinis. 

 aeropbilum. 

 brevicoUe. 

 longicolle. 

 inflexus. 



DESCRIPTION OF PLATE XX. 



Fig. 1. Strongylus tiibifex, $. Natural size. 

 Fig. 2. Tail of the same. Enlarged. 

 Fig. 3. Strongylus nodularis. Tale of male. 

 Fig. 4. The same. Caudal extremity of female. 

 Fig. 5. Strongylus acuticaudatus. Tail of female. 

 Fig. 6. The same. Caudal end of male. 

 Fig. 7. Strongylus spiculatus. Tail of female. 



Fig. 8. The same. Tail of male. . ' 



Fig. 9. Echinorhynchus inflexus. Natural size. 



Fig. 10. Head of the same. The lemnisci were twisted in the specimen 

 here drawn. Enlarged. 



Figures 3 to 8 inclusive are variously magnified, from 30 to 60 diameters linear. 



6. Characters of some New Species of American Fasseres. 

 By Philip Lutley Sclater, M.A., Ph.D., Secretary to 

 the Society. 



1. polioptila buffoni. 



Figuier a tete noire de Cayenne, Buff. PI. Enl. 704. — Motacilla 

 ccervlea, Gm. — Polioptila leucogastra, Sclater, P. Z. S. 1855, p. 12 

 {partim). 



Plumbea, siibtus alba : jnleo toto, alls et cauda nigris : tectricum 



alarum majorum marginibus externis, secxmdariorum pogoniis 



externis, caudce rectricibits duabus extimis et tertia ex majore 



parte albis : rostro et pedibus nigris, illius tomiis pallidioribus. 



Long, tota 4-0, alae 1'9, caudse 1-8, rostri a rictu 0"6 poll, et dec. 



Hub. In Guiana et Nova Granada int. 



Mus. P. L.S. 



Obs. Similis P. leucogastrce ex Brasilia, sed minor, et rostro lon- 

 giore, rectrice extima omnino alba, et harum secunda et tertia fere 

 usque ad basin albis dignoscenda. 



