ALCID^ — PHALEBIDIN^ : AUKS. 
809 
tail 1.25 ; tarsus 0.70; middle toe and claw 1.00; chord of culmen, including the node, 0.40; 
gape 0.60; height of bill at base 0.30, width scarcely less. In winter: The knob gone; 
the little white bristles of head retained ; white of under parts extensive, reaching far around 
sides of neck ; humeral and scapular feathers and many of the secondaries marked with white, 
producing patches of this color on the upper parts, unknown in other PhaleridioKS ; such 
seasonal change of plumage indicating an approach to Mergulus or Brachyrhamplms. Young : 
Like the adults, but the white of the under parts nebulated with dusky ends of the feathers; 
this clouding does not clear up until the knob of bill and bristles of head have been acquired. 
Fig. 545. — Least Auk, adult, nat. size. Fig. 546. — Least Auk, young, nat. size. 
This curious little bird, the smallest of all the auks, and one of the least of all water birds, 
inhabits the coasts and islands of the N. Pacific, resorting to favorite breeding places by 
millions, with S. psittaculus and S. cristatellus. The nesting is similar, the single egg being 
laid in the recesses of rocky shingle over the water; size 1.55 X 1.12. The bird is not known 
to come S. so far as the U. S. 
Fig. 547. — Group of Least Auks. (Designed by H. W. Elliott.) 
341. PTYCHORHAM/PHUS. (Gr. tttv^, tttvxos, piux, ptuchos, a fold ; pa^c^o?, hramphos, beak.) 
Wrinkle-nosed Auks. Size moderate; form stout; no crests nor any peculiar feathers 
about head. Bill about f as long as head, stout, straight, little compressed, conic-acute; 
culmen little convex, broad at base, where in the dried state transversely corrugated; in place 
of which wrinkles there may be some formation now unknown; sides of upper mandible 
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