158. 
159. 
PHALACROCORACIDA): CORMORANTS. 729 
P. viola/ceus. (Lat. violaceus, violet.) VIOLET-GREEN CorMmoRANT. Frontal feathers 
reaching culmen; gular sac inconspicuous, very extensively feathered, the feathers reaching on 
the sides of the under mandible to below the eyes, and running in a point on the sae far in 
advance of this. Small: length 24.00-28.00; extent about 40.00; wing 10.00-11.00; tail 
6.00 or less; tarsus 2.00 or less; bill along gape 3.00 or less, very slender, and smooth on 
the sides, its depth at base about 0.33. Deep lustrous green, including the back, the feathers 
of which are not margined; the scapulars, wing-coverts, and sides of the body iridescent with 
purplish or coppery, the neck with rich violet and blue; gular sac orange; feet black. Two 
median lengthwise crests as in the last two species. Among the specimens before me, one 
has no white Hank-patch, but a few white scattered plumes on the neck; another, marked 9, 
has none of these, but a large snowy tuft on the flanks. Pacific Coast of N. Am., very abun- 
dant in suitable places along the Alaskan coast; breeding on cliffs. (P. resplendens, Aud.) 
P. v. bair'di. (To S. F. Baird.) Barrp’s Cormorant. Like the last; very small, the 
wing being under 10.00, the tarsus 1.67, the gape 2.67; the bill extremely slender. Has 
both the flank-tufts and the neck-plumes; the sac in life said to be dusky studded with red. 
Possibly represents a small southern race, bearing somewhat the relation to violaceus that 
floridanus does to dilophus. Farallone Islands, Cala. 
56. Family PLOTIDZ: Darters. 
Bill about twice as long as the head, straight, slender, very acute, paragnathous, the 
toinia with fine serratures. Gular sac moderate, naked. Nostrils minute, entirely obliterated 
in the adult. Wings moderate, the 3d quill longest. Tail rather long, stiff, broad and fan- 
shaped, of 12 feathers widening towards the end, the outer web of the middle pair curiously 
crimped (in our species). 
There is an occipital style, as in cormorants, but it is very small. There are remarkable 
peculiarities of the cervical vertebra, in their conformation and articulation, the passage of 
tendons through bony eyelets, etc., a mechanism producing the strong kink observable 
near the middle of the neck, and the ability of the bird to thrust forward and retract the head. 
There are 20 cervical vertebrae in P. anhinga. The digestive system shows a remarkable 
feature ; instead of the lower part of the cesophagus being occupied by the proventricular 
glands, these are placed in a small distinct sac on the right side of the gizzard, which, as 
in other Steganopodes, develops a special pyloric cavity, the orifice of which ‘is protected 
by a mat of lengthy hair-like processes, much like cocoa-uut fibre, which nearly half fills 
the second stomach.” There is a single small coecum, as in herons. The tongue is very 
rudimentary. The carotid is single in P. anhinga. Sternum as in Cormorants. 
The darters are birds of singular appearance, somewhat like a cormorant, but much more 
slightly built, and with exceedingly long slender neck and small constricted head that seems 
to taper directly into the bill, the head, neck, and bill resembling those of .a heron. As in the 
Cormorants, there are long slender feathers on the neck ; the sexes are commonly distinguish- 
able, but the 9 is said sometimes to resemble the ¢. Other changes of plumage appear 
to be considerable, but not well made out. The feet are short, and placed rather far back, 
but the birds perch with ease. Unlike most of the order, they are not maritime, shunning 
the seacoast, dwelling in the most impenetrable swamps of warm countries. They fly swiftly, 
and dive with amazing ease and celerity. They are timid and vigilant birds; when alarmed 
they drop from their perch into the water below, noiselessly and with scarcely a ripple of 
the surface, and swim beneath the surface to a safe distance before reappearing. When 
surprised on the water, they have the curious habit of sinking quietly backward, like grebes; 
and they often swim with the body submerged, only the head and feck in sight, looking like 
some strange kind of water serpent. They feed on fish, which they do not dive down upon, 
i 
