MARSLPIATA. 105 



[The author enumerates three, to which four have since been added by Mr. Ogilby, and an eighth by M. Geoffroy. 

 These animals keep in holes of trees till twilinbt, and for an hour or two after sunset are observed eatin? the 

 leaves of the dift'erent Eucalypti ; also, in retired places, those with the youn? shoots of fruit-trees. The P/i. vul- 

 pina is known as the Brush-tailed Opossum in Van Diemen's Land, and the P/i. Cookii, as the Ring-tailed 

 Opossum.} 



The Petaurists (Petaurus, Shaw ; Phalangista, Illig.) — 



Have the skin of the flanks more or less extended between the legs, as in the Colugos, and Taguans 

 among the Rodents, by which they are enabled to sustain themselves iu the air for some seconds, and 

 to make greater leaps. They have been found only in New Holland. 



Some of the species still possess inferior canines, but extremely small. Their upper canines and 

 the three first molars, both above and below, are very pointed ; the back molars have each four points 

 [the last excepted, in which there are but three]. M. Desmarest has named this division Acrobat es. 

 [It possesses thirty-six teeth in all.] 



Tlie Pygmy Petaurist (Did. pigmtea, Shaw).— Of the colour and nearly the size of a Mouse ; the hairs of the tail 

 disposed very reg-ularly on its two sides like the barbs of a feather. 



Other species have no inferior canines, and the superior are very small. Their four back molars 

 each present four points, but a little curved into a crescent, somewhat as observed in the Ruminants. 

 Anteriorly, there are two above and one below, less complicated: this structure renders them still 

 more frugivorous than any of the preceding. [Their teeth amount in all to thirty-four.] 



The Great Petaurist (Did. petaurus, Shaw ; P. taguanoides, Desm.) — Resembles the Tagaun and the Colugo in 

 size: its fur is soft and thick, and the tail long and [not in those which I have seen] flattened: brown-black 

 above, white underneath. 



Tlie Sciurine Petaurist (Did. sciurea, Shaw). — Ash-coloared above, white beneath, and smaller than the pre- 

 ceding; a brown hne commencing on the muzzle and continued along the back : the tail tufted, and as long as the 

 body, its posterior portion black. From the islands near New Guinea. [It is abundant along the south coast of 

 New Holland. The teeth are forty in number, and exhibit considerable modification ; hence this animal has been 

 made a separate division of the Betidea, Waterh. There are but four true molars to each jaw, with comparatively 

 blunt tubercles originally ; three false molars and a middle-sized canine above, and four small flattened teeth 

 below : the palate also is in this group perfett, whereas it is not so in the two others. Four or five species are 

 known to possess these characters. 



Tlie remainder appertain to the same minimum group as P. taguanoides.] 



Our third subdivision possesses the incisors and superior canines of the preceding. The 

 two toes of the hind-foot are also similarly united ; but the posterior thumbs and inferior 

 canines are wanting. It contains but a single genus, 



The Potoroos {Hypsiprymnus, Illig.), — 

 Which are the last animals of this family that retain any trace of the general character of the Car- 

 naria. Their teeth are nearly the same as in the Phalangers, and they still have pointed canines above 

 [which all but disappear in one species]. Their two middle upper incisors are longer than the rest, 

 and pointed; the two inferior ones project forwards. They have anteriorly a long trenchant and 

 dentelated molar, followed by four others, each with four blunt tubercles. What particularly di.^tiuguishes 

 these animals, however, is their hind legs, which are very much longer in proportion than their fore 

 ones, that have no thumbs, and the two first toes of which are joined as far as the nail ; so that, at a 

 first glance, it seems as though there were but three toes, the middle one having two nails. They 

 often hop on their hind-feet, at which time they make use of their long and strong taU to support 

 themselves. They have accordingly the form and habits of the Kangaroos, from which they only dirl'er in 

 possessing the superior canine. Their regimen is frugivorous, and the stomach large, divided into two 

 sacs, and possessing several inflations ; but their coecum is moderate and rounded. 



Only one species is known, the size of a small Rabbit, and of a mouse-grey colour, which is termed the Kanga- 

 roo-rat (Macropus minor, Shaw.) [Five or six others have since been discovered, two of which, inhabiting New 

 Guinea, are remarkable for their arboreal habits, in reference to which their structure is slightly modified, the 

 bmbs being less unequal, and the great nails of their hind-feet cur\-ed : they do not, however, essentially dift'er 

 from the others. One species is common in the interior of Van Diemen's Land]. 



Tlic fourth subdivision differs only from the third in having no canines whatever. 



The Kangaroos, (^l/i7er07;«.?, Shaw ; Ilalmaturii.i, llHg.), — 



In which all the characters occur that we have assigned to the preceding genus, except that the upper 



