I(>\\\>>hM) AM) WJIMoltl: IMF Hllil>>. I(i7 



Structural <liarjutfrs M-paratiiif: tlu" two that Mr. Matlii-\vs oviT- 

 hK>kt'«l. Kr«)ni tin* scries axailaltic it stHMUs that Si-acophacthcm has 

 tho oixTculuni over the nostril hroader and hea\ ier, ami harhs on tlie 

 shiift.s of the two elonpite riK-trii-es on either side >rreatly re<hic<'d in 

 length. This hitter character is one l)y whi<-h S<-ae<»j)haethon may he 

 recognized at a jrhmcc. The l)hjck hue at the sich' of th*- hhick shaft in 

 1\ ruhriramlu.s is niisU-adinj: a-s it makes the shaft apjM'ar hroad and 

 strong while in reality it is the same size as the shaft in P. acthercus. 

 When old and much worn the central rectric«'s of l\ aHhcrruji l)e<'ome 

 narrowed and resemi»l<' those oi S-acophaethon hut may he distin- 

 guishtnl hy their ragged appearance. As the small-ljillcd I\ amrricanu.t 

 also has a strong broad operculum the basis of ditferentiation falls 

 upon differences in the tail alone. Th(*se are assumed here to be only 

 subgeneric in value an<l tiie He<l-tailed troi)ic-bird is kej)t in Phaethon. 



SULIDAE. 

 2. SuL.\ PiscATOR (Linne). 

 Pdeoanus piscalor Linn6, Syst. nat., cd. 10, 1758, 1, p. 134. (Java Seas). 



Three specimens of this booby were collected! at Tekokoto in the 

 Pauraotu Islands, 20 October, 1S99. None of these is in adult plumage 

 though all are one year old or more. One specimen, a male, has the 

 tail and head white, while the back and lesser wing coverts are hair- 

 brown. In the two remaining specimens the tips of the rectrices are 

 white and the rest of the plumage is dull. 



Mathews (Birds of Australia, 191 o, 4, pt. 3, p. 21G) states that 

 specimens of this boob\- from the Pacific Ocean are larger in every 

 dimension than those from the Atlantic region and that " the soft 

 parts seem to differ." For this reason he separates the Australian 

 bird under the subspecific name rubripcs Gould. Concerning the 

 color of the soft parts information of value is not available, but com- 

 parison of a series of skins from Pacific and Atlantic Ocean localities 

 fails to substantiate the claim made as to difference in size. So far 

 as measurements of wing, culmen, and tarsus go, sj)ecimens from the 

 Paumotu Islands are almost identical with birds collected by the 

 author on Desecheo Island, a small island l\"ing between Porto Rico 

 and Santo Domingo in the West Indies. Careful study of a larger 



