172 PROCEEDINGS OF THE ACADEMY OP 



2. Ps. Banksii Coues, ex Pach/plila Banksii Smith. Prion B. Gld. Procellaria 

 B. Schl. The fringe of serrations is apparent to the end of the bill. Chord of 

 cultnen 1-05 ; width of bill at widest point -50 ; height at base -44. 



3. Ps. turtur Coues, ex Proc. turtur Banks " icon. ined. No. 15." Also of 

 Kuhl ? Prion turtur Gld. The fringe of serrations is confined to the basal por- 

 tion of the bill. Chord of culnieu 1-00 ; height of bill at base -37; width -33. 



4. Ps. ariel Coue?, ex Prion ariel Gould. ? Proc. turtur Kuhl. Proc. arid 

 Schl. Halobcena typica Bp. ? Prion brevirostris Gld. Smaller than turtur. 

 Bill 9 to 10 lines, height 1\ lines ; width 3 to 4 lines. 



Genus III. Prion Lace"p. 1800 1. Serrations developed to the maximum. 

 Lateral lamellae hypertrophied, with inflated free edges. Culmen straight : 

 lateral outline of bill convex to the unguis. A deep sulcus on either side of 

 the culmen ; another on the lower mandible for reception of the fringe. Inter- 

 ramal space broad, nearly naked. Tail elongated, much graduated, contained 

 1 \ times in the wing. 



5. Pr. vittatus Lacep. ex Proc. vittata Gra. Pachi/ptila vitt. 111. Proc. Fors- 

 teri Lath. nee. Smith. Pachypt. Forsteri Swains. Proc. latirostris Bonn. Greatest 

 width of bill three-fourths of an inch or more. 



In a subsequent paper will be considered the Diomedeinx and Ilalodrominx. 



Critical Review of the Family PROCELLARIIDiE ; Part V ; embracing the 

 DIOMEDEIN.E and the HALODEOMINiE. With a General Supplement. 



BY ELLIOTT COUES, M. D., U. S. A. 



The group composed of the Albatrosses is so trenchantly distinguished from 

 all other Natatojes, that for its definite characterization it is only necessary to 

 advert to the absence of the hallux, and to the position of the rhinothecas. In 

 other morphological points the Albatrosses conform closely to the type of 

 structure which obtains throughout the Procellariinx. 



The Halodromes, if really components of the family Procellariidce, are the 

 most curiously aberrant of all the Gavix or Longipennine Natatores. They 

 appear to hold a quite anomalous position, intermediate between several nata- 

 torial suborders. The very short falcate wings, no less than the absence of the 

 hallux ; the general configuration of the body, and especially the position of 

 the posterior extremities relative to the axis of the body; as well as the com- 

 pactly imbricated, glossy plumage ; indicate a close aflinity with the Urinatores, 

 or Brachypterous Natatores. These structural resemblances are borne out by 

 the attitudes, habits, and mode of life of the species, so far as we are acquain- 

 ted with them ; which are rather those of Guillemots than of Petrels. The 

 dilation of the bill, particularly of the under mandible, and the partially naked 

 and distensible submental skin, which forms an imperfect pouch, point to a 

 type of structure extensively prevailing among the Totipalmi. Most of the lat- 

 ter have the rhynchotheca segmented ; so that almost the only character of the 

 Halodromes which is strictly Procellaridian is the tubulation of the rhinothe- 

 ca ; and even in this feature the details of shape and direction of axis are en- 

 tirely unique. So far indeed as external characters are concerned, arguments 

 are adducible for their reference to either of the three tribes above alluded to ; 

 and especially to the Urinatores. It remains for the scalpel to finally deter- 

 mine their true affinities. 



By Illiger* the tubulation of the rhinotheca has been made indicative of a 

 tribe {although called a family) Tubinares, which is attaching to it a value 

 coordinate with such a character as e. g. the membranous union of the hallux 



* Prodromus, 1811, p. 274. 



[May, 



