608 RODENTIA 



continues nearly parallel with outer margin of the bone to lambclal 

 suture, the two borders together producing a diamond-shaped 

 figure. Interparietal with antero-posterior diameter relatively 

 greater and tranverse diameter lelatively less than in Cricetus 

 cricetus. Interorbital region much narrower than rostrum, with 

 high lateral ridges and well marked median groove. Zygoma not 

 peculiar in general form, gradually spreading so that greatest 

 zygomatic breadth is at glenoid level. Anterior base of zygoma 

 peculiar in the complete absence of the forwardly extending 

 plate forming outer wall of infraorbital foramen in Cricetus, so 

 that when viewed from above the anterior margin forms an 

 unbroken curve to maxillo-premaxillary suture. The absence of 

 the outer plate causes the foramen to assume an oval outline 

 somewhat flattened on inner side. Rostrum not tapering 

 anteriorly, the width of the region immediately in front of 

 infraorbital foramina not increased by any evident swellings 

 over roots of incisors. Incisive foramina relatively shorter and 

 broader than in Cricetus cricetus, the outer margins slightly but 

 evidently spreading in front of suture, the posterior margins 

 extending to level of posterior margins of infraorbital foramina. 

 Palate relatively narrower than in Cricetus cricetus, but with no 

 special peculiarities of structure. Mandible with coronoid process 

 relatively longer than in Cricetus cricetus, its apex almost over- 

 hanging articular surface. 



Teeth. — ^^Upper incisor not producing any noticeable swelling 

 at front of infraorbital foramen, the shaft narrower internally 

 than externally, its transverse diameter and greatest antero- 

 posterior diameter equal, its anterior face nearly flat, sloping 

 conspicuously inward, so that those of the two teeth come 

 together at a noticeable angle ; cutting edge very oblique. 

 Lower incisor with shaft flattened in front and on inner side, the 

 outer and posterior borders evenly rounded, the antero-posterior ^ 

 diameter scarcely exceeding greatest transverse diameter. Molar 

 rows about two-thirds as long as diastema ; anteriorly the rows 

 diverge so slightly and the palate is so narrow that length of 

 tooth-row is distinctly greater than width of palate, including 

 both alveoli. Form, relative size, and general structure of molars 

 both above and below as in Cricetus cricetus, but backward pro- 

 longation of outer re-entrant angles in upper teeth, apparently 

 at all stages isolated as pits or islands, and width of re-entrant 

 angles in lower teeth greater relatively to area of tubercles. 



Measurements. — Head and body about 180 ; tail about 12 

 (well-made skins) ; hind foot in three adults, 19 mm. , ear from 

 meatus about 15. For cranial measurements see Table opposite. 



Speciviens examined. — Nine, from the following localities : — 

 Roumania: Malcoci, Dobrudscha, 7 (B.M. and U.S.N.M.). 

 Bulgaria : Melschka, near Bustchuk, 2 (Andersen). 



BemarTis. — Apart frgm the generic characters, its peculiar 



