Transactions of tke Linnean Society. 489 



of them had brought forth young previously to their arrival in England. 

 The teats in this individual were larger than in the other, apparently un- 

 impregnated, specimen, but subsequently diminished in size. Contrary 

 to the state of these organs in the Kangaroo, the anterior teats alone were 

 enlarged in the Phalangista gliriformis* Two beautiful figures of the 

 animal accompany the paper, which is further illustrated by a plate, giv- 

 ing various details of its organisation, so as to exhibit, in a much more 

 complete manner than is usually done, the whole of the generic charac- 

 ters with the exception of those derived from the teeth. 



In a paper " On a new Genus of the Order Rodentittj'" Mr. Brookes 

 describes fully the skeleton of an animal hitherto imperfectly known as 

 the Dipus maximus of M. Blainville. Contrasting its osteology with 

 that of the Dipus Sagitta Mr. Brookes finds in them so many and such 

 important differences, as to induce him to regard the two animals as ge- 

 nerically distinct ; and as the former is distinguished, by its dentary cha- 

 racters especially, from every known genus of the order, he proposes its 

 reception as anew one under the name of Lagostomus. Its characters 

 are thus given : " Denies incisores in utraque maxilla duo elongati, pro- 

 " minentes : maxillae inferioris canaliculati, paullo longiores : molares 

 " in utraque maxilla utrinque quatuor, obliqui, antrorsum extrorsiimque 

 " spectantes, corona siraplici laminate : maxillae inferioris obiiquiores 

 " bilaminati ; maxillae superioris tres anteriores bilaminati, posticus tri- 

 " laminatus. Pedes antici breviores, digitis quatuor : postici elongati, 

 '* validi, digitis tribus : ossa metatarsi digitis numero aequalia. Cauda 

 " medio'cris, pilis longioribus pectinatis vestita." To the single species 

 to which this generic character applies Mr. Brookes gives the name of 

 Lagostomus trichodactylus. He also adds some particulars to the pub- 

 lished descriptions of it, and furnishes detailed measurements of the more 

 important parts of the skeleton. Representations of the skeleton, of the 

 teeth and of the animal, the latter taken from the stufi'ed skin, accompany 

 the description. 



The ornithological papers are from the pens of Mr. Yarrell, Mr. Lead- 

 beater, and Mr. Douglas. To the latter we are indebted for " Obser- 

 " vations on some Species of the Genera Tetrao and Ortyx, natives of 

 " North America; with Descriptions of Four new Species of the former 

 " and Two of the latter Genus." The new species described are. 



