1863.] SPINE-TAILED SWIFTS. 99 



to extend from British Columbia through Mexico into Guatemala, 

 where examples were obtained by Mr. O. Salvin. 



I take this opportunity of giving a short synopsis of the American 

 species of the genus Chcetura *, which may be distinguished in the 

 following way : — 



Div. A. Hemiprocne. Majores (long. corp. maj. quam 6 poll.). 



Major; torque postico, angusto, albo I. semicollaris. 



Minor; torque unclique, latiore, albo 2. zonaris. 



Div. B. Ch^tura. Minores (long. corp. min. qu. 6 poll.). 



Torque rubro 3. ruHla. 



'dorso aeneo-nigro, uropygio vix pallidiore 4:. pelasgia. 



r^ iironvo-in fiilin-lnnso / gi'ture albo : pact, obscuriore 5. vauxi. 



Torque nulloi "'"opygio '^"''S'"'>^° j gutt. et pact, fuliginosis G.poliura. 



uropygio cinereo 7. cinereivenlris. 



l^ uropygio albo 8. spinicauda. 



The synonymy of the species stands nearly as follows : — 



A. Hemiprocne. 



1. Ch^tura semicollaris. 



Acanthylis semicollaris, De Saussure, Rev. Zool. 1859, p. 118. 

 Chcetura semicollaris, Sclater, Cat. Am. B. p. 282. 



Nigra ; semitorque postico angusto, albo. 



Long, tota 10, alae 10, caudse 3, poll. Angl. 



Hab. Mexico. 



Mus. P. L. S. 



This fine Swift is easily distinguishable from C. zonaris by its 

 larger size, and the entire absence of any traces of a white collar 

 below. M. de Saussure has not vouchsafed to inform us in what part 

 of Mexico he procured it. My specimen was obtained by exchange 

 from the Geneva Museum. 



2. Ch^tura zonaris. 



Hirundo zonaris, Shaw, in Mill. Cim. Phys. pi. 55. 



Hirundo albicollis, Vieill. Nouv. Diet. xiv. p. 524, et Gal. Ois. 

 pi. 120. 



Acanthylis albicollis, Sclater, P. Z. S. 1854, p. 10, et 1858, p. 59. 



Cypselus collaris. Max. Beitr. iii. p. 344; Temm. PI. Col. 195. 



Hemiprocne collaris, Nitzsch, Pterylogr. p. 123. 



Pallene collaris, Boie, Isis, 1844, p. 1(58. 



Hemiprocne zonaris, Sclat. et Salv. Ibis, 1860, p. 37; Cab. et 

 Heine, Mus. Hein. iii. p. 84. 



Acanthylis collaris. Gray, List Spec. Fiss. p. 15; Bp. Consp. 

 p. 64 ; Burm. Syst. Ueb. ii. p. 364. 



Chcetura zonaris, Sclater, P. Z. S. 1861, p. 79, et Cat. Am. B. 

 p. 282. 



Fusco-nigra ; torque undique, lato, albo. 



»Long. tota 9*0, alae 9'0, caudse 2-5. 

 * I think it doubtful whether Temminck's Cypselus senex (PI. Col. 397) is to 

 be referred to this genus or not. Bonaparte says " rectricibus minime mucra- 

 natis, sed rigidis" (Consp. p. 65). I have no example of this species. — P. L. S. 



