SKELETON OF MARSUPIALIA. 345 



In Phalangista Cookii, in Petaurus Jiaviventer, and Petauriis 

 sciureus, in Macropus major, and some other Great Kangaroos, 

 the bony palate is of great extent and presents a smooth surface, 

 concave in every direction toward the mouth ; it is pierced by 

 the two posterior palatine foramina at the anterior external angles 

 of the palatine bones, either Avithin or close to the transverse 

 palato-maxillary sutures. Behind these foramina, in the Kan- 

 garoo, there are a few small irregular perforations. The bony 

 palate is similarly entire in the Hypsipryrnnus ursinus. In 

 Macropus Bennettii there are four orifices at the posterior part of 

 the bony palate. The two anterior ones are situated upon the 

 palato-maxillary suture, and are of an ovate form with the small 

 end forward. The two posterior foramina are of a less regular 

 form and smaller size. In the Brush Kangaroo {JSIacropus Brunii, 

 Cuv.) the posterior palatal foramina present the form of two large 

 fissures placed obliquely and converging posteriorly. They en- 

 croach upon the posterior borders of the maxillary plate. Anterior 

 to these vacancies there are two smaller foramina, and posterior 

 to them are one or two similar foramina. 



In the Potoroos, Wombat, and Koala, the posterior palatal 

 openings are large and oval, and situated entirely in the palatal 

 bones. In Hyps, setosus they extend as far forward as the inter- 

 space between the first and second true molars ; in Hyps, murinus 

 they reach to that between the second and third true molars : 

 posterior and external to these large vacuities there are two small 

 perforations. In the Phalaugers, with the exception of Ph. 

 Cookii, the palatal openings are proportionally larger ; they ex- 

 tend into the palatal process of the maxillaries, and the thin 

 bridge of bone which divides the openings in the Potoroo, &c., is 

 w^anting ; the two perforations at the posterior external angles of 

 the palatine bones are also present. In the Virginian Opossum 

 the bony palate presents eight distinct perforations, besides the 

 incisive foramina; the palatal processes of the palatine bone 

 extend as far forward in the median line as the third molars : a 

 long and narrow fissure extends for an equal distance (three lines) 

 into the palatal processes both of the palatines and maxillaries : 

 behind these fissures and nearer the median line are two smaller 

 oblong fissures ; external and a little posterior to these are two 

 similar fissures, situated in the palato-maxillary suture ; lastly, 

 there are two round perforations close to the posterior margin of 

 the bony palate. 



In the Ursine Dasyure a large transversely oblong aperture is 

 situated at the posterior part of the palatal processes of the 



