A. Smith Woodward— Visit to American Museums. 455 



The anterior lower grinder lias six inner and five outer angles, 

 while the last lower grinder (Fig. 4) has three inner and three 

 outer angles, with five cement spaces, the anterior outer space being 

 distinctly smaller than the others. The anterior upper grinder 

 (Fig. 5) has four inner and four outer angles, with seven cement 

 spaces, the hindermost of the inner spaces being rudimentary. The 

 second upper grinder (Fig. 6) has four inner and three outer angles 

 with six cement spaces, the hindermost of the inner spaces being 

 again rudimentary. 



There is in the Museum of Practical Geology another specimen, 

 referable to this species, from the Brick-Earth of Murston, near 

 Sittingbourne, Kent. It comprises parts of both upper and lower 

 jaws, very much crushed, but with the upper incisors, and, fortunately, 

 one of the anterior lower grinders preserved. The pattern of the 

 last-named tooth, with its six inner and five outer angles, leaves no 

 doubt as to its belonging to Myodes torquatus. 



At the present day Myodes torquatus has a circumpolar dis- 

 tribution ; but is rare in Greenland, and is said not to occur in 

 Russian Lapland. 



Myodes Jemmus, Linn. 



Another specimen from Erith, in Mr. Spurrell's Collection, is to 

 be referred to Myodes lemmus ; it is a part of a lower jaw embedded 

 in matrix, with the two incisors and the right and left anterior 

 grinders in place ; there are also fragments of the upper jaw in- 

 cluding the right and left anterior grinders. 



The lower front grinder (Fig. 7) is characterized by four inner 

 and three outer angles, with five cement spaces ; while the upper 

 front grinder (Fig. 8) has three inner and three outer angles, with 

 five cement spaces. 



Myodes lemmus is living at the present day ; but is restricted to 

 Scandinavia and Eussian Lapland. 



The Rodents now known to occur in the Brick-Earth of the 

 Thames Valley are: — Castor fiber, Linn.; Spermophilus erythro- 

 genoides, Falc. ; Microtus (Arvicola) amphibius, Linn. ; Microtus 

 (Arvicola) ratticeps, Key. and Bl. ; Myodes torquatus, Desm. ; and 

 M. lemmus, Linn. 



VI. — Vertebrate Paleontology in some American and Canadian 



Museums. 



By A. Smith Woodward, F.G.S., F.Z.S., 



of the British Museum (Natural History). 



{Concluded from the September Number, page 395.) 



Washington. 



The collection of Fossil Vertebrata in the National Museum at 

 Washington is at present insignificant ; and the only type-specimens 

 observed by the writer are the fish-remains described by Prof. 

 Leidy under the names of Clnpea humilis, Cladocyclus occidentalis, 

 Phareodus acutus, and Lepidosteus simplex, besides some fragmentary 



