THE SKELETON OF THE POEPOISE. 405 



uncovered in consequence of the small size, tubercular form, 

 and backward position of the nasal bones. The squamosal 

 is relatively small, but has the characteristically cetacean, 

 large, zygomatic process ; this extends forwards nearly to 

 the posterior end of the supra-orbital process, and gives 

 attachment to the slender jugal. 



The periotic bones form a dense osseous mass, which is 

 ankylosed with the no less heavy and thick, scroU-shaped, 

 tympanic. The pars mastoidea of the periotic mass fits 

 pretty accurately into a recess of the chamber which has 

 already been described ; and is thus held in position in the 

 di"y skull, though it is very easily detached. 



WTien the tympano-periotic bone and all the facial bones 

 are removed, only two pair of foramina are visible in the 

 base of the skull. The anterior pair give exit to the second, 

 third, fourth, the anterior division of the fifth and the sixth 

 nerves, and these answer to the optic and sphenorbital fora- 

 mina. The posterior pair take the place of the oval, 

 posterior lacerated, and jugular foramina, and the pre- 

 condyloid foramina open into them posteriorly. The rami 

 of the mandibles are only united by a short symphysis. 

 The body of the hyoid is broad and hexagonal, and has two 

 slender, anterior, and two bi-oad and flat, posterior, cornua. 



In the natural position the fore limbs stand out from the 

 body with their flat sui-faces looking upwards and down- 

 wards ; the upper surface being directed a little backwards, 

 and the lower, a little forwards. The tuberosity of the short 

 humeras is directed forwards. The carpus contains six or 

 seven ossifications. The number of phalanges in the digits 

 is two, eight, six, thi-ee, two, counting the pollex as the first. 



The pelvic bones are elongated, slightly curved, osseous 

 styles. They lie with their long axes parallel to the vertebral 

 column, their convex sides upwards, and their smaller ends 

 forwards, within an inch of the centra of the vertebi-ee, 

 their hinder ends being close to the third chevron bone 

 of the tail. The front ends are about an inch apart. 

 Behind its centre, each bone presents a flattened thickening 

 for the attachment of the corpus cavernosum of its side. 



