Zoological Society, 67 



of the abdomen grey ; lower part of the abdomen and flanks black- 

 ish grey, crossed by broad irregular bands of grey ; bill and feet 

 olive -brown. 



Total length, 6 inches ; bill, f ; wing, 3 ; tail, 1| ; tarsi, 1. 

 Hab. Van Diemen's Land. 



Sterna velox. Stern, fronte, loris, colli lateribus, et corpore in" 

 feriore albis ; spatio circumoculari, occipite et nucha nigris ; cor- 

 pore superiore, alis, cauddque belle cinereis. 

 Forehead, lores, sides of the neck, and all the under surface white ; 

 space surrounding the eye, occiput, and back of the neck black ; all 

 the upper surface, wings and tail delicate grey ; outer web of the 

 external quill greyish black ; shafts of all the primaries white ; irides 

 blackish brown ; bill black. 



Total length, 13 inches ; bill, 21 ; wing, 9| ; tail, 6^ ; tarsi, |. 

 Hab. Bass's Straits. 



Hydrochelidon fluviatilis. Hyd. fronte, vertice, et nuchd 

 nigris ; corpore superiore, alis cauddque pallide cinereis ; facie 

 et guld albis, Ji6c colore gradaf\m ad pectus cinerescente, et hoc 

 ad abdomen necnon ad latera nigrescente. 

 Forehead, crown and nape deep black; all the upper surface, 

 wings and tail light grey ; sides of the face and the throat white, 

 gradually deepening into grey on the chest, and the grey into black 

 on the abdomen and flanks ; under surface of the shoulder and under 

 tail-coverts white ; irides black ; bill blood-red ; feet light blood-red. 

 Total length, 9f inches ; bill. If ; wing, 8f ; tail, 3^ ; tarsi, |. 

 Hab. Rivers and lakes of the interior of New South Wales. 

 Thalasseus Torresii. Thai, fronte, facie, et collo dorse su- 

 periore, partibusque inferioribus lucide albis ; plumis verticis et 

 illis oculos circumdantibus albis, guttd parvuld centrali nigrd no- 

 tatis ; occipite et nuchd nigerrimis ; dorso alisque saturate cinereis, 

 Cauda, pallide cinered. 

 Forehead, sides of the face and neck, upper part of the back and 

 all the under surface silky white ; feathers of the crown and sur- 

 rounding tlie eye white, with a minute spot of black in the centre 

 of each ; occiput and back of the neck black ; back and wings deep 

 grey ; tail grey ; primaries greyish black, broadly margined on their 

 inner web with white ; the shafts white ; irides dark brown ; bill ochre- 

 yellow ; feet blackish grey. 



Total length, 13| inches; bill, 2|; wing, 11^ ; tail, 4 J ; tarsi, 1, 



Hab. Port Essington. 



Nearly allied to S. poliocerca, but much smaller in size. 



Sternula nereis. Stern, vertice et nuchd nigris, hoc colore ocu- 

 los cingente maculamque anteriorem efficiente, ut non in frontem 

 ducto ; fronte albo ; dorso alisque belle ex argenteo- cinereis ; cor- 

 pore inferiore, uropygio et caudd albis. 

 Crown of the head and back of the neck black, which colour ex- 

 tends round the eye, and is continued in the form of a spot before 

 that organ ; but this colour does not extend on to the forehead, which 

 is white ; back and wings delicate silvery grey ; the outer web of the 



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