CAROTIDS—CARPUS 77 
the Ratitz, Podicipes, several Steganopodes, Alca, Otis, Turnix, 
Megapodiide, some Old-World Psittaci, Merops, Buceros, Upupa, 
Trogonidz, Cypselide, Colius, all the Pici and Passeres. 
4, One carotis conjuncta, but the right root alone is present, 
the left being obliterated. ‘“ This carotis primaria dextra ” is likewise 
deeply lodged, as in the 2nd and 3rd cases, and has hitherto been 
observed only in Eupodotis. 
In the following three cases, one or two collateral and super- 
ficially-placed arteries take the place of one or both deep carotids. 
5. A carotis primaria s. profunda dextra coexists with a carotis 
superficialis s. collateralis sinistra. All the American and a few 
Old-World Parrots are such “ Aves bicarotidine abnormales” (Garrod). 
6. Two superficial carotids, a right and left, are present, the 
deep or primary vessels being entirely obliterated. Hitherto only 
c.p.d. C.p.S. C.p.S. 
c.p. d. €.S.S. 
DIAGRAMMATIC REPRESENTATION OF SOME OF THE VARIATIONS OF THE CAROTID ARTERIES. 
Ao. Aorta; su.d. A. subclavia dextra ; su.s. A. subclavia sinistra; ¢.p.d. A. carotis profunda 
dextra; c.p.s. A. carotis profunda sinistra; c.p.c. A. carotis profunda conjuncta; c.s.s. A. 
carotis superficialis sinistra. 
A, normal condition, two separate deep carotids; B. the two deep carotids fused into one, 
e.g. Ardea; C. the same as B, but the root of the left carotid is reduced, e.g. Phoenicopterus ; 
D, the left deep carotid is lost, but supplanted by a superficial vessel, e.g. certain Psittaci. 
observed by Ottley (P.Z.S. 1879, p. eo as an individual varia- 
tion x Bucorvus abyssinicus. 
The only carotis is a c. superficialis sinistra, all the other 
ones being lost, observed by Forbes in Orthonyx spinicauda (not 
in O. ochrocephala), this being the only exceptional case of all the 
Passeres hitherto examined. 
It is clear that the 2nd case is directly referable to the Ist, that 
the 3rd and 4th are each independently developed from the 2nd, 
and that the 5th, 6th, and 7th cases are recent and very qualified 
modifications. The undoubtedly independent acquisition of these 
carotid characters renders them valueless for taxonomic purposes, 
except within smaller and well-defined groups, ¢.g. the Parrots (see 
also VASCULAR SYSTEM). 
CARPUS (adj. carpal), xapros ; the wrist or articulating region 
between the forearm, or ulna and radius, and the hand. In adult 
