296 PROCEEDINGS OF THE ACADEMY OF 
Length of disc 17 in.; of head and neck 19 in. 6 lin.; total, four feet. Length 
of sternum 20 in. 6 lin, 
Habitat.—The Rembo and Ovenga rivers, tributaries of the Fernando Vas, 
Equatorial West Africa. 
Not having at hand specimens of the Aspidonectes niloticus of W. and S. 
Africa, we bave been unable to compare the only specimen of the as pilus with 
it; their differences are, however, sufficiently obvious. In the latter the sternal 
callosities are much smaller, and the anterior pair have their anterior and 
posterior borders nearly parallel, and the outline of the inner semicircular. 
The tail is shorter, and the colors are brownish green with white and yellow 
spots. 
The Old World Aspidonectes possess eight pairs of ribs; we do not 
know how it is with the American species, as there are no authentic specimens 
in the Acad. mus., but our Amyda and Glatypeltis have but 7 pairs. 
EMYDOSAURIA. 
Crocodilus marginatus (eoffr—Brought by Mr. Duchaillu, from the 
Ogobai. This species is principally abundant in the Cape colony, but is found 
in other parts of Africa. 
OPHIDIA. 
COLUBRIDA—CALAMARIN.E. 
OLISTHENES nob. 
Head scarcely distinct from the body, depressed, especially in front. Muzzle 
elliptical in outline, projecting much beyond the under jaw, as does also the 
superior labial region. At the posterior extremity of the superior maxillary 
bone are two curved teeth, larger than the other maxillaries, separated from 
them by an edentulous space, and grooved in front. Cephalic shields normal. 
Vertical broad; loral small. Rostral prominent, broad, dividiug the anterior 
frontals somewhat; not recurved. Preocular 1, postoculars 2. Urosteges and 
anal shield entire. Scales very smooth. 
O. euphaeus nob.—Scales subequally hexagonal on the flanks, more elon- 
gate on the back, very little imbricate; ia nineteen rows. The rows diminish in 
number upon the tail, by two or more running together upon the dorsal region, 
thus forming short series of from four to six scales twice or thrice the usual 
width. Vertical plate broad, hexagonal, the anterior angle very obtuse, the 
posterior acute, dividing the occipitals. Superciliaries rather small, broader 
behind in consequence of the convergence of the sides of the vertical. Posterior 
froutals large, extending on the side of the head half way along the preocular. 
Anterior frontals rather small. Nostril between two nasals; the anterior large, 
separating the rostral and first labial, and nearly reaching the edge of the 
mouth. Rostral broad, triangular, depressed, slightly dividing the anterior 
frontals. Postoculars two. Superior labials eight, the first three small, the 
eye resting on the fourth and fifth. Pupil erect, elliptical. Inferior labials 
eight, the fourth largest, and in contact with the posterior geneials, of which 
there are two pairs. 
Gastrosteges 205, anal 1, urosteges 75. 
Color uniform brown, dark on the head and anterior part of the body, lighter 
posteriorly, and pale beneath. 
Length 2 ft. 9 in. 6 lin. Tail 17 in. 6 lin. 
Had Dr. Gtintber placed his Hologerrhum philippinum among the Calama- 
rinz, instead of Scytalian Colubridew, we should have felt well satisfied in re- 
cording this as a second species of that genus; we are not positive indeed, that it 
may not yet be so considered; but with our present k: owledge we must distin- 
guish it generically. The head of this serpent is very Calamarian in its indistinct- 
ness from the body, its depression and projecting rostral. Besides these, a broader 
vertical and more distinctly divided rostrals distinguish it from Mologerrhum. 
[Nov 
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