94 Mr. 0. Salvin on the Costa-Rican Bell-bird. 



bers of the genus Cephalopterus (Umbrella-birds), one species of 

 which is said to gather its throat-lappet under its throat in a 

 bunch like a rose {vide Fraser in P. Z. S. I860, p. 67) *. A mus- 

 cular contraction would cause one of these caruncles to become 

 more rigid, as in the familiar case above cited. 



The actual use and economy of external appendages such as 

 those possessed by birds of this genus is extremely obscure. 

 Their possession by the male only, certainly indicates that the 

 special benefit conferred upon the species is sexual, the result of 

 "sexual selection," to be classed with the more brilliant plumage 

 found in the males of so many birds. Similitudes sometimes 

 suggest themselves in most dissimilar objects. Do not the 

 curious appendages of this bird recall the long pendents of the 

 Costa-Rican Orchid, Cypripedium caudatum ? 



The series of specimens now before me includes a presumed 

 female without caruncles, and males in all stages of dress. It 

 is well worthy of remark that the caruncles seem to commence 

 their growth on the assumption of the adult plumage, and that 

 they acquire their full development almost before the fully adult 

 feather is assumed, showing that their growth must be very 

 rapid. The upper caruncle from the bill first shows itself, the 

 two rictal commencing later and growing unevenly. 



In the Brazilian C. variegatus this rapidity of the growth of the 

 gular caruncles does not seem to be the same. The young bird 

 in almost adult dress, before referred to, has these caruncles quite 

 small ; they look like feathers that have not yet burst their cases. 



In their description of C. tricarunculatus, MM. Verreaux 

 suppose, from analogy with the other members of the genus, 

 that the adult plumage of this species would be white — an idea 

 only partially warranted, C. variegatus being an exception to the 

 rule laid down. Dr. Cabauis, proposing the name C. leucocepha- 

 lus for the Costa-Uican bird, in the paper before quoted, places 

 too much stress upon the difference of locality of Dr. v. Frant- 

 zius's specimens and those of MM. Verreaux, where he says that 

 very probably MM. Verreaux were right in their suggestion re- 



* Mr. Eraser's personal observations simply state that he could not in- 

 flate the lappet "by blowing into the mouth or nostrils" (P. Z. S. 1859, 

 p. 143). There is nothing here to confirm the common report of the bird 

 being able to " inflate the neck-appendage to nearly 3 inches in diameter.'' 



