CAROTIDS-CARPUS 



77 



the Eatitse, Podicipes, several Steganopodes, Alca, Otis, Turnix, 

 MegapodiidcV, some Old-World Psittaci, Merops, Buceros, Upupa, 

 Trogonida?, Cypselidse, 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 

 sixperficialis s. collateralis sinistra. All the American and a few 

 Old-AVorld Parrots are such " Aves bicaroiidina} ahnormales " (Garrod). 



6. Two superficial carotids, a right and left, are present, the 

 deep or primary vessels being entirely obliterated. Hitherto only 



c.p.d.^ r^c.p.s. 



C.p. c. 



c.s.s. 



su.s. 



A. B. C. D. 



Diagrammatic Repeesentation of some of the Variations of the Carotid Arteries. 



Ao. Aorta; si(,f7. A. subclavia dextra ; su.s. A. subclavia sinistra; c.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 snperficialis 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. Phojnicopterus ; 

 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. 461), as an individual varia- 

 tion of Bucorvus abyssinicus. 



7. The only carotis is a c. superiacialis sinistra, all the other 

 vessels being lost, observed by Forbes in Orthonyx spinicauda (not 

 in 0. ochrocephala), this being the only exceptional case of all the 

 Passeres hitherto examined. 



It is clear that the 2nd case is directly referal)le to the 1st, 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 Avithin smaller and well-defined groups, e.g. the Parrots (see 

 also Vascular System). 



CARPUS (adj. carpal), KapTro? ; the wrist or articulating region 

 between the forearm, or ulna and radius, and the hand. In adult 



