208 
Birds of Gambia. 
STERCORARIin^ 
I think I have occasionaJIy t^■eoll a .sin^'lc Skua off Batluirst. 
[f so it must have been of the two followimg, which ran be dis- 
till g'uished by their sizes and shape of theif tails. Rieliardson's Skua 
is the smaller, 18 inches iu length, and lias a pointed tail, wliile 
the length of the other species is 21 inches and its tail moi-e 
rounded. 
Stercomrius crepkl-atiis. RICHARDSON'S SKUA. 
Range. Circumpolar and Sub-Arctic Regions. African, In- 
dian, and Au.strali<an Seas; South Brazil in winter. (H.L). 
S. pomulorhimis. ROMATORHINE SKUA. 
Bange. Arctic Regions; Australian, African, and South 
America,n Seas in winter. (H.L.) 
PROCELLARIID^ 
Of this large family of maritime birds my knowleilge is 
prOiCtically nil and I cannot even do foi' them the little I have 
attempted for the Gulls, but for the sake of completeness give a 
list of those, within the rainge of which the Gambia is geographically 
included. Their haunt, too, being the open ocean, their inclusion 
in our avifauna (if indeeif they should be included at all) would de- 
pond on chance visitors. 
Procetilarki pelagioa. STORM-PETREL. 
Ra<n,g\e. North Atlantic Ocean to West Africa. Western Med- 
itemiineain. (H.L.) 
P. leucorrhoa. FORK-TAILED PETREL. 
Range. Northern seas of both hemispheres. (H.L) 
P. ca.itro. CANARIAN FORK-TAILED PETREL. 
Ramge. Cape Verde Islands. South Atlantic to Madeira; 
Galapagos Islands; Hawaii. (H.L.) 
Ocea>nUe.'i oceanica. WILSON'S PETREL. 
Range. Atlantic and Indian Oceans to the Antarctic, Aus- 
tralia and New Zealand. (H.L.) 
Fregetta melnnogaster. DUSKY-VENTED PETREL. 
Range. Southern Oceans to North Atlantic. (H.L.) 
Puffinus gravis. GREATER SHEARWATER. 
Ram-ge. Atlantic Ocean south to Cape Seas; Falk lands. 
(H.L.) 
P. kuhli. MEDITERRANEAN SHEARWATER. 
Rmige. Mediterranean ; Atlantic south to Kerguelen I. 
(H.L.) 
P. oh.scurii.s. DUSKY SHEARWATER. 
Rainge. Tropical and Sub-tropical Oceans. (H.Tj.) 
P. assimilU. ALLIED SHEARWATER. 
Range. Australia; Atlantic north to Madeira. (H.L.) 
P. grisen.s. SOOTY SHEARWATER. 
Range. Atlantic and Pacific Oceans; south to Australia and 
Magellan Straits. (H.L.) 
Oestrefflfa mollis. SOFT-PLUMAGED PETREL. 
