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Show 448 MR. W. A. FORBES ON T H E [May 16, (5) In the very slight development of the ascending plates of the palatines, well represented in the other group. (6) In the small amount of ossification in the interorbital septum, this, in the Motmots, being nearly entirely osseous. (7) In the shape of the sternum, this having four distinct and deep notches (the outer pair being far the larger) never converted into foramina, and separated by delicate xiphoid processes. In the Motmots the inner pair at least (Hylomanes), but usually both (Momotus, Baryphthengus, Eumomota) are converted into smallish foramina. (8) In the tendency to bifurcation of the manubrium sterni. (9) In possessing 8 sacral and 7 caudal vertebrae, as opposed to 11 and 6 in the Momotidae1. (10) In the oil-gland having a large tuft of plumes on its apex, this being quite or almost altogether absent in the Momotidae. (11) In the better development of the rictal and mandibular vibrissae. (12) In the ocreate tarsus, which is very long, whereas in the Momotidae it is transversely scutellated and short. (13) In the much greater syndactylism of the toes. (14) In the less development of the outer pectoral branch of the inferior tract, which, in Momotus at least, is given off much nearer the anterior margin of the breast, and diverges much more than in Todus. (15) In the shape of the tongue in the Motmots, apically frayed-out and brush-like, and with the lacerations of the margin directed forwards, not backwards. (16) In the possession of large and well-developed intestinal caeca, these being completely absent in all the Motmots. (17) In the triangular shape of the obturator internus, this in the Motmots being oval. (18) In the conformation of the syrinx. Of special points of resemblance between Todies and Motmots I am unaware of any that can be considered characteristic of these two families as a group, the points in which they do approach each other being equally met with in other allied birds. Thus the simple dorsal tract of Todus and Momotus reappears in Alcedo, as do the crenulated beak-margins in Merops". Neither is the termination of the expansor secundariorum muscle on the teres peculiar to the two groups in question, as it is found, as already observed, in some Kingfishers, as well as in Steatornis. The resemblance between the termination of the tensor patagii tendons in the two families is perhaps the best-marked feature of 1 In all the Momotidae I have examined (including the genera Momotus> Bcmjphthengus, and Hylomanes) this is the number of these vertebrae, the total being 37, except Baryphthengus, which has only 36, by the reduction of its dorsal vertebrae to 4 (C. 15, D. 4, S. 11, Cd. 6=36). Dr. Murie, after stating the number of the vertebrae in the Motmots to be 36, 37, or 38, curiously enough gives the number characteristic of Todus (35) as one of the characters of his group " Serratirostres," in which he includes the Motmots (Ibis, 1872, p. 410) ! 2 As already pointed out by Murie, Ibis, 1872, p. 398. |
