The Swifts 



Large supraocular plates numerous — six; 

 marginal scales numerous and minute; dark 

 green, with a pale, greenish band on each side — 

 these separated by about fourteen rows of 

 scales; two series of obscure blotches; size 

 large. variablu swii-t, 5. variabilis. 



Gray, with wavy, darker cross-bands. An 

 indistinct stripe on each side — these separated 

 by about ten rows of scales. Size small. Head 

 plates not always corrugated. Occurs from 

 Atlantic to Pacific Q)asts. 



co.M.MON SWIFT, S . undiilatus. 



Scales more bristling than preceding; blotches 

 rather triangular. Occurs on the Pacific coast 

 only; size small. 



PACIFIC SWIFT, 5. undulatiis, var. occidentalis. 



Pale bands separated by six or eight rows of 

 scales; otherwise very similar to i'. undiilatus. 

 Size small. Restricted to Texas. 



Thayer's swift, 5. ihayeri. 



Olive-gray; a very narrow, but bright yel- 

 low line on each side — these lines about twelve 

 scale rows apart. Two series of dark crescents 

 on back; size small. 



striped SWIFT, S. scalaris. 

 Division D. A double series of moderaie-siied, supraocular 

 plates, bordered internally with a row of smaller 

 scales and externally by one or two rows of 

 small scales — which latter rows may be of ir- 

 regular formation. 

 Sub-division 1. A broad, jet-black collar, completed aboi'e. 



Scales very large and bristling. Obscure, 

 dark cross-bands on olive ground; a broad, 

 black collar, margined with yellow and com- 

 pleted above. Size very large. 



collared swift, S.torquatus, var. poinsettii. 

 Sub-division W. No collar; pale bands on sides. 



Olive gray. A pale band on each side, about 

 two scales wide and separated by about eight 

 scale rows. Obscure cross-bands. Size moder- 

 ate. SAGE-BRUSH SWIFT, S. graciosus. 



Following is a descriptive list of the species: 



The first group of the Spiny Swifts to be considered, is 

 Division A of the key, with which the inner border or margin 

 of small scales along the edges of the supraocular plates is in- 



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