160 MICROTIN^ 



one seems to have paid any attention to Forsyth Major's sugges- 

 tion. In the latter year the present writer, ^ with the aid of 

 excellent material, established the fact that two species have 

 left their remains in European Pleistocene deposits and showed 

 that neither could be identified with any of the living forms now 

 recognized. 



7. t Dicrostonyx gulielmi Sanford. 



1870. Arvicola gulielmi Sanford, Q.J.G.S., 26, p. 125, pi. viii, fig. 2. 

 1870. Lemmns torquatus, var. Sanford, loc. cif., pi. viii, fig. 4. Not 



of Pallas, 1779. 

 1872. Myodes torquatus Forsyth Major, Atti Soc. Ital. Sci. Nat. Milan, 



15, p. 124. 

 1880. ''.Myodes torquatus major Woldrich, Sitzungsb. d. k. Alcad. d. 



Wien, math. nat. CI. 82, Abth. 2, p. 25 ; based on fossil remains 



from a fissure deiiosit at Zuzlawitz, near Winterberg, Bohemia. 

 1901. Dicrostonyx torquatus Bate, Geol. Mag., [4], 8, p. 105. 

 1910. Dicrostonyx gulielmi Hinton, Ann. Mag. Nat. Hist., [8], 6, p. 38. 



Co-types. — Taunton Museum. 



Type locality and Horizon. — Hutton Cave, Somersetshire. 

 Late Pleistocene. 



Nomenclature. — Sanford's " Arvicola gulielmi" based upon 

 five lower jaws of Dicrostonyx from the late Pleistocene deposit 

 in Hutton Cave, would be specifically as indeterminable as 

 Pomel's " Arvicola (Myolemmus) ambiguus " were it not for the 

 fact that, under the name of " Lemtnus torquatus, var.," Sanford 

 described and figured, at the same time and from the same cave, 

 a fragmentary skull which evidently belongs to the same species. 

 No more precise information as to the provenance of the skull 

 and lower jaws than that contained in the words " from a 

 Somersetshire cave" is given by Sanford in his paper; but the 

 labels in his handwriting still preserved in Taunton Museum 

 indicate that all came from Hutton Cave. The skull in question 

 clearly belongs to the larger European Pleistocene species with 

 cheek-teeth of the D. torquatus type, and it is convenient to treat 

 it as though it were the type of the species, although the specific- 

 ally indeterminable mandibular rami are the actual co-types. 



Characters. — Size large (dental length in adults up to 20 mm.). 

 Cheek-teeth essentially as in D. torquatus. 



Skull large ; the nasals much expanded in front, their com- 

 bined width equal to half the nasal length ; zygomatic arches 

 very heavy ; anterior palatal foramina short and broad ; palate 

 boldly sculptured, with the postero-lateral bridges usually in- 

 complete ; presphenoid reduced to a slender bar ; teeth very heavy. 



Cheek-teeth (Fig. 71, 4) essentially as in D. torquatus, but 



larger and broader. In m^ and m^ the posterior walls of the 



liinder inner triangles are not reduced, but retain their thick 



enamel and primitive concave curvature; and there is in each 



» Hinton, Ami. Mag. N.H., [8], 6, p. 37. 



