399 



2235. The teeth from the left side of the upper and lower jaws of the Mm decuma- 

 nus, separately displayed. Hunterian. 



2236. The skull of the Jullador Rat (Mus indicus). 



The projection of the base of the socket of the lower incisor forms a prominent feature of 

 the ascending ramus outside the root of the condyloid process. 



Presented by Dr. Patrick Russell, F.R.S. 



2237. A right inferior incisor of a large Rat, which from want of apposition has con- 

 tinued to grow until it has formed one complete circle and the segment of a 

 second. Presented by Sir Joseph Banks, Bart., P.R.S., 



"With the following translation of an extract from a letter in Spanish, which he received with 

 the specimen : 



" I send it you that you may admire the extraordinary tooth of this Little animal. Believe 

 me, it is true, it was found in the Nazareth Garden (to which order I belong), near the Bar 

 (entrance to the port), and when it was killed I took the tooth : I know not its virtues, nor 

 have the natives ever discovered them." 



2238. The skeleton of the common Mouse (Mus musculus). 



The vertebral formula is : 7 cervical, 12 dorsal, 7 lumbar, 4 sacral, and 27 caudal. 



Hunterian. 



2239. The skeleton of the common Mouse (Mus musculus}. 



The vertebral formula is : 7 cervical, 12 dorsal, 6 lumbar, 4 sacral, and 27 caudal. 



Presented by Henry Cline, Esq. 



2240. The skeleton of the common Mouse (Mus musculus). 



The vertebral formula is : 7 cervical, 12 dorsal, 6 lumbar, 3 sacral, and 2& caudal. 



Presented by William Cliff, Esq., F.R.S. 



2241. The skeleton of the Australian Brown-footed Rat (Musfuscipes). 



The vertebral formula is : 7 cervical, 13 dorsal, 6 lumbar, 2 sacral, and 28 caudal. The 

 second dorsal is distinguished, as in the rest of the genus, by the superior length of its spi- 

 nous process : the eleventh dorsal spine is that towards which those of the other trunk-ver- 

 tebrae converge. The tubercle of the first rib abuts against the diapophyses of the seventh 

 cervical and first dorsal. The pleurapophysis of the sixth cervical underlaps its neck. Seven 

 pairs of ribs directly join the sternum, which consists of six bones. The anapophysis becomes 

 distinct on the eleventh dorsal, and disappears in the penultimate lumbar. The diapophyses 



