NATURAL SCIENCES OF PHILADELPHIA. 297 



the description written by himself as the more infallible test, than the figure 

 drawn by another, and therefore more liable to error. A figure of that which 

 coincides exactly with Dr. Gray's description will shortly be published. 



It may be mentioned that the teeth of Delphinus erebennus, stated by 

 me to be truncate like those of the D. tu r s i o, on the authority of Dr. S. J. 

 Howell, are found on examination to have an exceedingly oblique truncation 

 behind, extending from the alveolar line to the apex. 



PosToroRiA calvertexsis (Delphinas calvertctisis) Harlan, Proc. National In- 

 stitution 1842, 195. 

 This extinct species differs specifically from the recent P. b lain vil lei of 



the Southern Atlantic Ocean. 



Sibbaldids laticeps Gray. 



Catalogue Cetaceans, Mus. Britt. 170. Bakcna rostrat.a Eudolphi, Berlin 

 Abhandl. 1820. 



An examination of the skeleton of the cetacean described by Prof. Talia- 

 ferro, Proc. Acad. 1866, page 8, and now deposited in the museum of the 

 Academy by Dr. P. A. Taliaferro, has shown it to be the above named 

 species, which is therefore to be added to the United States Fauna. 



Length from end of muzzle over convexity of back, forty-six feet nine 

 inches ; girth about nineteen feet: length from end of muzzle to axilla, (ex- 

 ternal measurement, ) fifteen feet ; breadth of head across inferior margin of 

 jaws, eight feet. Length of the pectoral extremity four feet, greatest breadth 

 fifteen inches; they were situated close behind the angle of the mouth. There 

 were 3(;0 lamina? of black baleen, extending on either side of the mouth about 

 six feet along the jaw, the longest about eighteen to twenty inches. The head 

 was acute. The folds of the throat many and capacious. The dorsal fin was 

 represented by a conical mass covered by horny integument, without any 

 membranous appendage, situated well posteriorly. The body near the tail 

 very slender. The flukes suddenly expand to a breadth often feet. The ver- 

 tebral line from the dorsal fin to the flukes, with six or eight knobs or humps. 

 Color, jet black above, including flippers, below white, sides beautifully 

 marbled by a combination of the two colors. 



ft. in. 



Total length of cranium 10 3 



Length supraoccipital to inferior margin of foramen magnum 2 7 



" o. maxillare from orbital process frontal 6 3 



Width do. at 3 ft. 1 in 7*5 



Breadth cranium from posterior angle to angle of orbital processes 



of frontal 4 8 



From latter to plane posterior angle supraoccipital 2 2 



Width supraoccipitals behind 3 3 



" nasal meatus anterior to o. o. nasalia 925 



The supraoccipital overarches on each side, a lateral longitudinal concavity, 

 which passes under or downwards, behind the horizontal frontal plates. Su- 

 perior inner edge of frontals raised ten inches above these orbital plates. Pre- 

 maxillaries only three inches in diameter, leaving a wide median gap on top 

 of the muzzle. 



The os hyoides has very little longitudinal extent, the body being 9 inches 

 long, while the base of each ceratohyal is 5*5 inches across; body most pro- 

 longed posteriorly, where it is narrowed, truncate, and with a deep longitudi- 

 nal fissure. 



The scapula is, as described for the species, like that of a Beluga, of con- 

 siderable longitudinal extent, and furnished with long coracoid and acromion. 



Of the anterior extremity, the humerus is less than half the length of the 

 radius, thirteen inches long, with the articular surfaces for ulna and radius 

 nearly equal. 



1866.] 



