able fact that when the rectrices in question first appear they are narrower at the points where the nibbling occurs, and where they will be ultimately denuded, than they are elsewhere. But an inheritance of this particular acquired character can hardly be asserted.

An aftershaft is present, but small.

The tensores patagii are simple, and there is no biceps slip. There is a fleshy pectoralis propatagialis. The tensor brevis consists of two parallel tendons, the anterior of which does not give off a wristward slip. The fan to the ulna arises in M. brasiliensis and M. æquatorialis as a continuation of the hinder of the two tendons, in M. Lessoni between them. Hylomanes gularis agrees with the first. The anconaus has a humeral slip. The somewhat rudimentary expansor secundariorum only reaches the margin of the teres.

The deltoid is large; its attachment to humerus is longer in Hylomanes than in Momotus (-). There is a separate tendinous scapular slip.

The muscular formula of leg is AXY-. Both peroneals are present. The deep flexor tendons of the motmots are rather peculiar in their structure. It will be observed that the slip to the hallux is given off before the flexor hallucis joins the flexor longus.

The first gluteal (gl. maximus) is only present in front of the acetabulum. The glutaus externus is absent as a distinct muscle, but the insertion of glutaus II. extends so far round the head of the femur that it may represent also the otherwise missing muscle.

The gizzard is stronger in Hylomanes than in Momotus, and is almost 'ptilopine' in section.

The tongue is long, bifid at the apex, and worn into filaments. In the alimentary canal the cæca are absent; the intestines measure fourteen inches in M. Lessoni, eighteen inches in M. brasiliensis. The right lobe of the liver is the larger, and there is a gall bladder.

There are two carotids. The femoral vein is abnormal. The syrinx has been described by GARROD and is figured by him. It does not apparently differ widely from genus to

genus. The last few tracheal rings are fused, but there is not a complete pessulus.

The motmots have fifteen cervical vertebra. The atlas is perforated by the odontoid process. C1-5, C11-D3 have median hypapophyses; on C14-D2 are a pair of inferolateral processes, which gradually approach the median line until they spring from a common base in D1, and are just visible as rudiments towards the tip of the hæmapophysis of D2. In Hylomanes there is also a double hypapophysis on C10. Three or four ribs reach the sternum, which has (Momotus) four foramina, or (Hylomanes) two notches and two foramina, and a bifid spina externa. The skull is desmognathous and holorhinal. The lacrymals are rudimentary; the ectethmoids are very small and do not nearly reach them. Nares impervious, pervious in Hylomanes.

The West Indian todies (Todidae) form a very distinct family; their structure has been chiefly investigated by MURIE and FORBES.2 They are small birds with feet in which the syndactylism is more marked than in motmots and some others. The annexed cut shows that the digits IV. and V. are united together as far as the end of the third phalanx of the one and the second of the other. The oil gland is tufted.

The skull is very imperfectly desmognathous. The two maxillo-palatines are not united together; they are completely free from each other and from a median ossified nasal septum. There seems to be no vomer. The descending portion of the lacrymals is large and broad; the ectethmoids, on the other hand, are small. The interorbital septum is widely fenestrate. There are fifteen cervical vertebræ. The intestines are, according to Mr. FORBES, remarkably short, not measuring altogether more than 3 inches; on the other hand the cæca are as remarkably long (considering the sys

On the Skeleton of Todus,' &c., P. Z. S. 1872, p. 664.

2 On some Points in the Anatomy of the Todies (Todida), and on the Affinities of that Group,' ibid. 1882, p. 442. See also REICHENOW, Ueber das Genus Todus,' &c., Journ. f. Ornith. xxxi. 1883, p. 430.

tematic position of the bird); they measure about one-third of an inch. The cæca are narrowed at their origin from the gut, and, as in the owls, &c., dilated apically. The deep plantar tendons vary from the arrangement common to the group in that the slip to the hallux is given off before the blending of the two. The arrangement, in fact, is as in the motmots. There is an expansor secundariorum ceasing at the axillary margin of the teres, in the gallinaceous fashion. The syrinx has at the middle a bony box, which is formed of three or four bronchial rings united with about two tracheal rings. It is

only ventrally that the fusion is complete. The intrinsic muscles cease at the last tracheal ring but one.

The Galbulidæ are a family of neotropical birds, comprising the genera Galbula, Urogalba, Jacamerops, &c., and known as puff birds.

They are zygodactyle, with a nude oil gland, twelve rectrices, and a small aftershaft.

The pterylosis of Galbula rufoviridis is as follows:

The inferior tract is double from the angle of the jaw; just before leaving the neck each tract gives off a short branch, about six rows of two feathers, which runs on to the

margin of pectoralis. The main tract itself is also only two feathers broad. It sends off, about halfway down sternal keel, a short curved outer branch, which runs outwards and then forwards towards axilla, nearly meeting a second outer branch which is given off by the tract on opposite side to the inner branch, already spoken of. The dorsal tract has a slight break; the very short interscapular fork is of strong feathers and connected with posterior part only by a very few feathers which are weak and arranged uniserially.

The tongue is long and thin, tapering to a filament anteriorly; a gall bladder seems to be absent. In a specimen of G. rufoviridis the intestinal measurements were as follows: s. i., 4.15 inches; 1. i., 75 inch; cæca, 7 inch.

The Galbulidæ have an expansor secundariorum, but no biceps slip. The tensor patagii brevis tendon of Galbula has no wristward slip. It is merely a single tendon; in Urogalba there is a wristward slip.

In the leg the formula of Galbula is AXY, of Urogalba AX, both birds, of course, lacking the ambiens. The glutaus I. and V. are absent, at any rate in Galbula. The plantar tendons are picine.

Both carotids are present.

The skull of the Galbulidæ is very like that of the Bucconida; but there are nevertheless points of difference.

In Urogalba paradisea there is a long gap in the bony palate in front of the conjoined maxillo-palatines, as in Bucconida; but the palatines are more sloped off posteriorly, and their posterior halves are more closely in contact. The descending process of the lacrymal is broader, and it is perforated by a large foramen. In Jacamerops and Galbula, on the other hand, the descending process of the lacrymal is very slender.

The ectethmoids are large and the interorbital and intranarial septa complete.

There are fourteen cervical vertebra; the sternum has two pairs of incisions.

BUCEROTES

Definition.-Oil gland tufted. Muscle formula, AXY. Ceca absent. Skull desmognathous.

The well-marked family Bucerotidæ contains at least two distinct genera, Buceros and Bucorvus. The latter (the ground hornbill) is entirely African; the former, which has been much subdivided, is both African and Asiatic.

The great casque,' not always equally developed, and the long bill, frequently serrated along its margins, and the largely black and white or black plumage distinguish these birds. But the small Toccus is a less typical form. The syndactyle foot, in which the second and fourth toes are united to the third-the latter for several joints, the former for only one-is highly distinctive, and is repeated in the ground-living Bucorvus.

The oil gland is tufted. The feathers have no aftershaft.

There are ten rectrices.

The pterylosis of Bucorvus abyssinicus has been described and figured by NITZSCH.

The neck is completely feathered, except at its lower end, both dorsally and ventrally. The former is the commencement of the very narrow dorsal space of a long oval form, but not extensive. The pectoral tracks diverge at end of neck, but are subsequently undivided.

The carotids are double in Bucorvus; the left only is present in others. The remarkable obliteration of the carotids in the former genus, and their replacement by a pair superficial in position, have been described by GARROD2 and OTTLEY.3

The tensores patagii are in some ways characteristic of the Bucerotida. In Buceros convexus (cf. FÜRBRINGER)

OWEN, On the Anatomy of the Concave Hornbill,' P. Z. S. 1833, p. 102. 2. On a Peculiarity in the Carotid Arteries. . . of the Ground Hornbill, P. Z. S. 1876, p. 60.

A Description of the Vessels of the Head and Neck in the Ground Hornbill,' ibid. 1879, p. 461.