STEGANOPODES. 179 



curious original of the aceompanyiiig woocl-cut, the South American boat-bill (C. 

 cocMeariun) is the object of considerable diversity of ojjinion. To all external 

 a])pearance, with the exception of tlie remarkal)lo bill, whieli is gi'eatly dej)ressed and 

 dilated laterally, the lateral outline much bowed, the boat-bill is a night-heron, that is, 

 its general projiortions, size, ornamental feathers, and coloration are those which char- 

 acterize the night-herons. But while it resembles a night-heron, and originally may 

 have sjirung from the same stock, it is modified and siieeialize<l in so many ways and 

 so inij)ortant features, besides the bill and the conseijuent alteration of the skull, that 

 we necessarily must regard Mr. Robert Ridgway's view as the most justifiable of the 

 two mentioned above. As sjiecializations additional to the strange conformation of 

 the beak may be mentioned that the boat-bill has lost both the femoro-caudal muscle 

 and the feather tufts on tiie oil gland, and that it has acquired a fourth pair of 

 powder-down jiatches. Grading our groups on a somewhat different ]irinciple, how- 

 ever, we include the two sjiecies of boat-bills (a new sj)ecies from Central America 

 having been desci-ibed this year by the last-named gentleman as Cochlearius zelecloni) 

 in the sub-family Cochleariinre. 



At first sight the Cochlearius seems to represent a j)igmy Balseniceps, between tlic 

 legs of which it can stand upright witliout bending its neck, and the view of their 

 being closely related has also been urged by different authorities ; but we cannot help 

 thinking that Professor Reinhardt was right when he ojiposed Professor W. K. Par- 

 ker's opinion to that effect, for, as Reinhardt remarks, even the outward likeness 

 between the two bills is, on nearer inspection, by no means so great as would appear 

 at first sight. Tlie bill of Cochlearius is remarkably flattened, and not so much calcu- 

 lated for great streuLTth as for great roominess; and this is still more increased by the 

 naked <lilat:ible skin between the branches of the lower jaw, which can be distended 

 into a complete pouch or bag hanging down as far as the throat. 



Order X. — STEGANOPODES. 



Notwithstanding the shortness of the legs and the ' Steganopodous ' character of the 

 toes, — that is, the connection of all four toes by membranes, — the birds of the present 

 order are unquestionably nearly related to the Ilerodii. Like these, they are desmo- 

 gnathous, and lack basipterygoid processes; "but the inner edges of the palatine bones 

 unite for a much greater distance behind the ]>osterior nas.al aperture, and a median 

 ridge is sent down from the line of junction of the palatines." Authors have been 

 equally unanimous in asserting the great homogeneity of the group, until Professor 

 St. G. Mivart, in 1877, in his valuable memoir, "On the Axial Skeleton of the Pele- 

 canida>," raised doubts as to the propriety of referring the tropic-birds and friu^ate- 

 birds to the Stcganojjodes, though it is not quite correct to say that, " according to hiiTi, 

 the tro])ic-birds are wrongly placed with this order." Here are his own words; 

 "Besides \_Pelecanus, Sula, Phalacrocorax, and Ploti(s],i\»i two genera Frefjata and 

 Phaethon are usually classed with them to contribute to the group of the 8teganopo<les. 

 But, from the point of view here adopted (that of the postcr.anial part of the axial 

 skeleton only), I have found it impossible to detect ch.aracters which seem to me good 

 and sufticient to unite such Steganopodal groups together, and at the same time divide 

 them off from other forms." It ajjpears, however, that in the above-mentioned struc- 

 ture of the palate and the feet, which Mivart, together with the rest of the cranium 

 and the extremities, intentionally excluded from his comparison, there are characters 



