1H/G.] MR. A. H. GARROD ON THE ANATOMY OF COLIUS. 419 



PlCIFORMES. PvSSERIFORMES. 



With tufted oil-gland and With nude oil-gland and 



without caeca, with caeca. 



{Pici. Passeres. 



Captioning. Bucconidce (? as to caeca). 



Ramphastina. Trogonidce. 



UpupidcB. Merop'ulce. 



(Collides). Galbulidce. 



Bucerotidtc. Caprimulyidcp. 



Aleedinidce. f Coraciidce. 

 \ Momotidce. 



From what has been said above it is evident that Co/ius must be 

 included among the Piciformes, and near those of this division with 

 a left carotid only, a four-notched sternum, and a blended plantar- 

 tendon arrangement. No other piciform bird, however, combines all 

 these characters. In the Alcedinidae the sternum and plantar ar- 

 rangement correspond ; in the Bucerotidae Toccus agrees as to the 

 carotid and the plantar tendons. The Picidae (Picinae + Capitoninse -f- 

 Ramphastinae) have a left carotid, a two-notched sternum, but a spe- 

 cialized plantar-tendon distribution. Consequently the fact that the 

 combination of characters is unique justifies us in retaining the Co- 

 liidae in a separate family, related on the one hand to the Picidee, and 

 on the other to the Alcedinidae and Bucerotidae. 



Something must be said with reference to the probability of Culius 

 having psittacine affinities. It is an interesting fact that in those 

 species of the genus Cacatua (galerita, leadbeateri, moluccensis, ike.) 

 in which the oil-gland is not lost, the resemblances (oidy accidental 

 I assume) to the genus Co/ius are peculiarly numerous. In these 

 Cacatuce there is a left carotid artery only, no ambiens muscle, and a 

 myological formula A,XY. Nevertheless I hope that in my paper 

 on the Order Psittaci * the impression left by its perusal is that the 

 Parrots all sprang straight away from a stock with two carotids and 

 an ambiens muscle. Such being the case, and Coitus most certainly 

 not being a true Parrot, the arguments in favour of its having arisen 

 independently from the psittacine ancestor, and of its having under- 

 gone (also independently) cacatuiform modifications during the 

 progress of its evolution, are less easy to accept than those which 

 suppose it to have sprung, as I have above assumed, from the less 

 specialized stock whence has been derived all the Anomalogonatee. 

 The form of the sternum and the distribution of the plantar tendons 

 are in favour of this view of the question. 



It may be mentioned that the syrinx of Coitus (which has been 

 figured by Johannes Miillerf in a closely allied species) is most 

 nearly related to that of Ceryle among the Kingfishers. 



* P. Z. S. 1874. p. 586. 



t Ueber die bisher unbekannton typischen Verschieclenheiten der Stimmen? 

 organe der Passerinen, 1847, pi. v. figs. 9-12. 



