18G6,] MR. SCLATER ON THE AMERICAN CAPRIMULGIDCE. 123 



and very numerous, and run into each other so as to produce a sort 

 of running pattern. 



Length nearly \ inch ; breadth about \ inch. 



Hab. California {IF. Newcombe, Esq.; Mus. Brit.). 



DESCRIPTION OF PLATE XII. figs. 1 & 2. 



Fig. 1. Lepidicrus angasii, p. 122. 

 1 a. Whole animal, natural size. 

 1 b. Anterior portion seen from beneath. 

 1 c. Abdominal portion, to show the spines. 



1 d. Abdominal portion, to show tail-flap. 



Fig. 2. Estheria newcombii, p. 122. 



2 a. Natural size. 

 2 b. Dorsal view. 

 2 e. Ventral view. 



2 d. Portion of carapace highly magnified to show the structure. 



5. Notes upon the American Caprimulgidce. By P. L. 

 Sclater, M.A., Ph.D., P.R.S., Secretary to the Society. 



(Plates XIII., XIV.) 



In the notes upon the American representatives of this family of 

 birds which I have to offer to the Society I shall confine my remarks 

 to such specimens as I have had au opportunity of examining myself, 

 not venturing in this very difficult group to give any opinion upon 

 species unknown to me. 



The principal authorities I have to refer to upon the subject are 

 (1) Mr. G. R. Gray's list of the specimens of this family in the 

 British Museum*, published in 1848, (2) Mr. Cassin's 'Catalogue 

 of the Caprimulgidce in the Collection of the Academy of Natural 

 Sciences of Philadelphia' (1851), and the same naturalist's critical 

 remarks upon the American species published in the ' Proceedings ' 

 and 'Journal' of the same Academyf, and (3) Burmeister's account 

 of the Brazilian species of this family in his ' Syst. Uebersicht d. 

 Thiere Brasiliens ' (vol. ii. p. 370 et seq.). As regards the northern 

 species, our best authority is of course Professor Baird's * Birds of 

 North America.' 



Before, however, I speak of the American species of Caprimulgidce 

 known to me, I will commence with a few preliminary observations 

 upon the whole of the family, and its geographical distribution. 



The Caprimulgidce, as they are usually limited, present us with 

 two very different types of structure in their feet, which enable us 

 to separate them readily into two divisions. The first of these affords 

 us one of the few known instances of deviation from the normal rule 



* List of Specimens, &c., part 2, sect. I., Fissirostres. 



t " Notes on an Examination of the Birds of the Family CatprmiulgidcB, &c." 

 (Proc. Acad. Phil. v. p. 175, 1851); and " Monograph of" the Birds composing 

 the Genera Hgdropsalis, Wagler, and Antrostomus, Nuttall " (Journ. Acad. Phif 

 ser. 2. vol. ii. p. 113). 



