108 GENERAL ORNITHOLOGY. 



beiug hidden in the feathered cere, which, therefore, might easily be mistaken for the bird's 

 forehead. A sort of false cere occurs in some water birds, as Jaegers or Skuas gulls (geuera 

 Stercorarius and Megalestris). The tumid nasal skin of Pigeons is sometimes called a cere; 

 but the term had better be restricted to the birds first above named. The under mandible 

 probably never presents softeuing except as a part of general skinniness of bill ; it may have 

 a nail at the end, as it does in the Duck family (Anatida). (b) The covering is either entire 

 or pieced. In most birds it is entire — that is, the sheath of either mandible may be pulled off 

 whole, like the finger of a glove. But in many birds it is divided into parts by various lines <if 

 slight connection, and then comes off in pieces; as is the case with some water birds, particu- 

 larly Petrels, where the divisions are regular, and the pieces have received distinctive names. 

 Thus the pieces which I named in 1866 for the Albatross are : culminicorn, along ridge of bill; 

 latericorn, along each side of upper maudible ; unguicorn, on the hook of the bill ; naricorn, 

 encasing each nostril ; ramicorn, along each side of under mandible ; inferior unguicorn, at 

 tip of under mandible, and interramicorn, between the two lower edges of the inferior ungui- 

 corn. Many Auks (Alcidce) also have the covering of the bill in particular pieces, and it is an 

 extraordinary fact that such parts are of a secondary sexual character, being assumed at the 

 breeding season and afterward moulted like feathers. Such condition of the sheath, or of 

 its special developments, is called caducous or deciduous. The entire covering of both jaws 

 together is called rhamphotheca (Gr. pdfi.(f)os, hramphos, beak; 6rjKT), theke, sheath): of tlie 

 upper alone, rhinotheca (Gr. pi's, hris, nose) ; of the under, gnathoiheca (Gr. yvddos, gnathos, 

 jaw); but these terms are not much used, nor are dertrotheca (Gr. beprpov, dcrtron, hook) 

 and myxotheca (Gr. /xv|a, Lat. myxci) for the superior and inferior uuguicorus, respectively. 

 (c) The covering is otherwise variously marked ; sometimes so strongly that similar features 

 are impressed upon the bones beneath. The most frequent marks are various ridges (Lat. pi. 

 carince, keels) of all lengths and degrees of expression, straight or curved, vertical, oblique, 

 horizontal, lengthwise, or transverse; a bill so marked is said to be striate (Lat. stria, a streak) 

 or carinate ; when numerous and irregular, the ridges are called rugce (Lat. ruga, a wrinkle), 

 and a bill is said to be corrugated or rugose. When the elevations are in points or spots in- 

 stead of lines, thev are called puncta (Lat. pnmctum, a point) ; a bill so furnished is j)unctate, 

 but the last word is oftener employed to designate the presence of little pits or depressions, as 

 in the dried bill of a Snipe toward the end. Larger softish, irregular knobs or elevations pass 

 under the general name of warts or papillae, and a bill so marked is liapillose ; when the pro- 

 cesses are very large and soft, a bill is said to be carunculate (Lat. caro, flesh, diminutive 

 carunculus, little bit of flesh). Various linear depressions, often but not always associated 

 with carina?, are grooves or sulci (Lat. stdcus, a furrow), and the bill is then called sidcate. 

 Sulci, like carinas, are of all shapes, sizes, and positions; when very large and definite, they are 

 sometimes called canalicuJi, or channels. The various knobs, " horns," and large special fea- 

 tures of bill cannot be here particularized. Any of the foregoing features may occur on both 

 mandibles, and they are exclusive of that special mark of the upper, the nasal fossa in which 

 the nostrils open, and which is considered below. We have still to notice special parts of either 

 mandible ; and will begin with the simplest, the 



Under Mandible (mandibula, or maxilla inferior). — In most birds this is a little shorter 

 and narrower and not nearly so deep as the upper mandible ; sometimes quite as large, or even 

 larger. The upper edge, double (i. e., there is an edge on both sides), is called the mandibu- 

 lar tomium, or in the plural, tomia (Gr. rip-vfiv, temnein, to cut ; fig. 26, j ) ; this is received 

 against, and usually a little within, the corresponding edge of the upper mandible. The 

 prongs already mentioned are mandibular rami (pi. of Lat. ramus, a branch ; fig. 26, i) ; 

 these meet at some point in front, either at a short angle (like >) or with a rounded joining 

 Clike p ) ; in either case this is called angidus menti or mental angle. At their point of union 



