PHALACROCOBACID^ : CORMORANTS. 729 



758. P. viola'ceus. (Lat. violaceus, violet.) Violet- green Cormorant. 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 sac far in 

 advance of this. Snuill : 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 

 tlie 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 witli 

 purplish or coppery, the neck with well 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 tiank-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.) 



T59. P. V. bair'di. (To S. F. Baird.) Baird's CORMORANT. Like the last; very small, the 

 wing being under 10.00, the tarsus 1.67, the gape 2.67 ; the biU 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 dilopJms. Farallone Islands, Cala. 



56. Family PLOTID^E : Darters. 



Bill about twice as long as the head, straiglit, slender, very acute, paragnathous, the 

 toinia with fine serratures. Gular sac moderate, naked. Nostrils minute, entirely obliterated 

 in the adult. Wings moderate, the 3d quiU longest. Tail rather long, stifi", 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 smaU. There are remarkable 

 peculiarities of the cervical vertebrae, 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 oesophagus being occupied by the proventriculai- 

 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-nut 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 biU 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 weU 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 fi'om 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 neck in sight, looking like 

 some strange kind of water serpent. They feed on fish, which they do not dive down upon, 



