Microtus (Stenocranius) gregalis (Pallas)
Baculum: Length of stalk (2.4 mm.) 1-3/4, times greatest breadth, 4-1/3 times greatest depth; median ossified process well developed, more than 1/3 length of stalk, higher than wide, slightly bowed, closely appressed to terminus of shaft; basal tuberosities of stalk moderately developed, confluent medially, posterior profile of medial apex rounded in dorsal view, lateral indentations present, hence trilobate outline; in proximal end-view base wider ventrally, ventral concavity broader than dorsal concavity but of equal depth, medial constriction 2/3 greatest depth; shaft slender in distal part, inflated terminally, and wider than high at mid-point of stalk; lateral profile a smooth slope of gradually decreasing curvature from point of greatest width to near distal end.
The baculum of this species figured by Ognev (1950:461) differs in having lateral ossified processes, and a more rounded base of the stalk. Resemblance to the New World _Stenocranius_ is discussed below.
_Specimen examined_: One from "Eastern Europe," 8059.
Baculum: Length of stalk (2.8 mm.) 1-1/2 times greatest breadth, 3-1/2 times greatest depth; median process ossified, 2/5 to 3/5 length of stalk, laterally compressed, sometimes arched in dorsoventral plane; lateral processes cartilaginous, slender; basal tuberosities well developed, averaging less enlarged than shown in Figure 32, but more angular in lateral outline than shown in Figure 33; tuberosities confluent posteriorly; posterior profile smoothly rounded to trilobate, curvature at point of greatest breadth usually acute; in proximal end-view base wider dorsally, deep dorsal concavity, shallow ventral concavity, medial constriction 3/5 of greatest depth; shaft slender anteriorly, at mid-point of stalk twice as wide as high, at tip higher than wide, laterally inflated; lateral profile in most specimens abruptly curved anterior to point of greatest breadth.
The single specimen of the Old World _M. (Stenocranius) gregalis_ examined resembles the New World _M. (Stenocranius) miurus_ in the angular lateral profile at the point of greatest breadth of the stalk, slender shaft in comparison to broad base of stalk, and presence of a single well-developed laterally compressed median process. The base of the stalk in the baculum of _M. gregalis_ is less well developed and smaller than in the baculum of _M. miurus_.