1870. | ON THE @SOPHAGUS OF SAUROPSIDA. 283 
vated. As I have not made an examination of the osteology of these 
birds, I will merely point out that there is a remarkable osteological 
difference in the orbit of Dacelo from that of Alcedo and Ceryle, 
which is at once apparent on removing the skin from the crown of 
the head, the lachrymal bone in the former bird attaining the deve- 
lopment so characteristic of the Falconidee and Strigidz, in which it 
contributes to roof-in the eye. 
DESCRIPTION OF PLATE XXIV. 
Fig. 1. Muscles of back of neck of Ceryle stellata: a, a’, upper and lower bellies 
of biventer cervicis (aponeurotic sheath removed on each side); *, trans- 
verse tendon ; 4, longus colli posticus ; ce, complexus. 
2. Muscles of back of neck of Dacelo gigas: a, a’, upper and lower bellies of 
biventer cervicis; b, aponeurotic sheath retained on left side; ce, tra- 
pezius; d d, latissimus dorsi. 
3. Muscles at back of neck of Alcedo ispida: a, a’, upper and lower bellies 
of biventer cervicis (aponeurotic sheath removed). 
4, Viscera of Dacelo: a, trachea; b, bronchus; ¢, gland ; d, esophagus; ¢ 
lymphatic gland; f, heart; g, liver; %, stomach; @, conyolutions of 
intestine; *, cloaca. 
5. Oil-gland of Dacelo gigas. 
6. Oil-gland of Alcedo ispida. 
7. Orbit of Dacelo: 7, lachrymal. 
8. Orbit of Alcedo: 7, lachrymal. 
2. On the Taxonomic Characters afforded by the Muscular 
Sheath of the Gisophagus as regards Sauropsida and 
other Vertebrata. By Grorce Guuuiver, F.R.S. 
This paper is intended to show that the subject of it deserves 
more attention than it has yet received ; to which end some of the 
results of my observations will be briefly noticed, referring for more 
particulars to my descriptions in the ‘ Proceedings of the Zoological 
Society ’ for September 10, 1839, June 14, 1842, and April 22, 1869. 
And if, by now again calling attention to the question, it should 
receive such additional investigations as may lead to a more accurate 
and extensive knowledge of the taxonomic value of the cesophageal 
sheath, the object of the present communication will be attained. 
Although more than a quarter of a century has passed since the 
observations above cited proved that either the comparative distri- 
bution, or presence, or absence, of the transversely striped muscular 
fibre of the cesophagus may afford good diagnostics between certain 
large groups and subsections of Vertebrates, and Leydig has con- 
firmed my results as to the deficiency of this fibre in the cesophageal 
sheath of Sauropsida, these facts have not yet been entertained in the 
books of systematic zoology and comparative anatomy. 
This neglect may have been caused by the complete investigation 
of the subject being somewhat tedious, requiring extensive examina- 
tions with good instruments, and relating to morphological arrange- 
se is 
