NO. 1116. PROCEEDINGS OF THE NATIONAL MUSEUMS 543 



GEOSPIZA PROPINQUA, Ridgway. 



(Plate LVII, fig. 7.) 



Geospiza propinqiia, Ridgway, Proc. V. S. Nat. Mus., XVII, No. 1007, Nov. 15, 

 1894, p. 361 (Tower Island, Galapagos Archipelago ; collection of Dr. G. Banr). 



Specific characters. — Very similar to G. coniroslris, llidg'way, of Hood 

 Island, in size and general form, bnt bill still narrower, with the cnlmen 

 more convex terminally, and the mandible relatively narrower and 

 more compressed; wing- slightly shorter. Wing, 2.95-3.15; tail, 1.85- 

 1,95; cnlmen, 0.82-0.90; width of mandible across rami 0.23-0.26, of 

 maxilla in front of nostrils 0.22-0.20; tarsus, 0.90-0.95; middle toe, 

 0.G8-0.75. 



Range. — Galapagos Archipelago: Tower Island (Banr and Adams). 



Adult male. — Type, No. 597, collection of Dr. G. Banr; Towxr Island, 

 September 2, 1891. Entirely black, with the plumage abruptly slate- 

 gray basally; bill blackish, the mandible inclining to dusky horn gray; 

 legs and feet dusky. Wing, 3.10; tail, 1.90; cnlmen, 0.85; width of 

 mandibular rami, 0.23; width of maxilla in front of nostril, 0.23; tarsus, 

 0.95; middle toe, 0.68. 



This form so closely resembles G. conirostris that at first I was inclined 

 to consider it the same, notwithstanding the wide separation of the two 

 localities. A closer examination, however, disclosed the fact that while 

 in the Hood Island specimens the under mandible is decidedly broader 

 at the angle than tlie upper, the Tower Island specimens have the two 

 mandibles of practically equal width. Thus, considering the lateral 

 profile of the bill as a cone, and the cnlmen as representing the right- 

 hand margin, the commissure would in G. conirostris intersect the cone 

 obliquely so as to throw the broader section to the left, while in G.irro- 

 pinqua the line would be exactly vertical, thus dividing the cone into two 

 equal sections. Diagrammatically, the difference may be expressed 

 thus : 



G. coiiirofifrifi. G. propinqua. 



While so similar in its lateral aspect, however, a vertical view of the 

 bills of these two species shows that of G. propinqva to be much more 

 compressed than that of G. conirostris, the width of the mandible 

 between the base of the rami being much less than the length of the 

 gonys, instead of just the same, thus throwing G. propinqua on the 

 " Cactornis^^ side of the line. 



Adult males of this species have very much less black on the under 

 tail coverts than those of G. conirostris. In the latter, these feathers 

 are black with white margins, while in G. propinqua they are light buff 

 with a median wedge-shaped mark of black. 



