Plate VI. 



PTILOGONYS CAUDATUS. 



(LONG-TAILED PTILOGONE). 



Ptilogonys caudatus 



Cabanis, Jour. f. Orn. I860, p. 402. 

 Baird, Rev. Am. Birds, i. p. 413. 



<?. Cmereus, coUo undique cum crista et gula pallide flavicantibus ; annulo oculari aureo ; pileo summo pallide 

 cinereo; alis nitenti-nigris, tectricibus extus cinerascentibus : cauda3 rectricibus lateralibus graduatis, harum inter 

 medus elongatis, omnibus nitenti-nigris, quatuor utrinque externis macula alba in pogonio inter iore donatis : hypo- 

 chondriis olivascescenti-flavis, crisso aureo: rostro et pedibus nigris : long, tota 9-0, ate 3-8, caud© rectr. ext. 3-6, 

 med. 5-2.^ Foem. Olivacescenti-cinerea fere unicolor, flavido mixta; pileo summo pure cinereo ; annulo oculari aureo : 

 alis caudaque sicut in mari, sed obscurioribus : cauda minus elongata. 



Sab. in Costa-rica, regione elevata: Kancho Eedondo (Carmiol) ; Volcan de Cartago (Arce). 



For many years the only recognized species of this form was P. cmereus, of Swainson, 

 described by that author in his Synopsis of the birds of Mexico, published in the year 1827, and 

 subsequently figured in his " Zoological Illustrations." This bird, which is very well known in 

 collections, inhabits the uplands of Mexico and Guatemala. The merit of the discovery of 

 a second species in the highlands of Costa Eica is due to Dr. von Frantzius ; its scientific appella- 

 tion having been bestowed upon it by Dr. Cabanis in his memoir on the birds of Costa Eica above 

 referred to, which was mainly drawn up from specimens transmitted to Berlin by the former 

 naturalist. 



The two species forming the sole members of the genus Ptilogonys, though evidently 

 closely allied, are easily recognizable by very trenchant characters. They must nevertheless be 

 considered as representing one another in the countries to which they belong, and as such of 

 great interest with reference to the geographical distribution of birds in Central America. 

 Similar instances of representative species in these two highland districts occur : for instance, 

 the Costa-Eican Chlorophonia calojphrys represents the Mexican C. occipitalis ; Diglossa plumbea 

 replaces D. baritula, and CMoramas albilinea, C. fasciata. These two districts though forming 

 portions of continuous land are in fact islands of cold climate in a sea of heat ; and we find 

 instances of zoological dissimilarity precisely analogous to what occurs in geographical islands 

 surrounded by sea. The difference of temperature between the highlands and lowlands forms 

 in such cases as complete a physical barrier as the ocean itself. 



We have no precise account of the habits of the Long-tailed Ptilogone, but they are 

 doubtless very similar to those of its northern ally, Ptilogonys cinereus, which is the only other 

 known species of the genus, and from which it is at once distinguishable by its elongated tail.* 



* For the full synonymy and description of these two species, see Prof. Baird's " Beview of American Birds," 

 i. p. 412, et seq. 



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