Diagnostic characters of the mammae and bacula between
E. smithi and
E. kageus were studied in specimens of 47 females and 71 males collected from five localities in Honshu and one in Shikoku, Japan. The specimens of each locality are composed of pregnant females, postpartum (non-pregnant) females with the open pubic symphysis, and males with the baculum in which three digital processes fully ossified.
Lack of the right or left pectoral nipple, and a small pectoral nipple on both sides or either side were found in nine specimens at four localities. Females with a normal-sized pectoral nipple on both sides were collected together with ones lacking it on both sides at three localities. The variation of the pectoral nipples in the females with the open pubic symphysis seems greater under postpartum conditions than in pregnancy. Mammary glands were absent in the pectoral part of all females examined, although present in the inguinal part.
Two-way table of the baculum characters showed independency between the contour types on the posterior border of the stalk and on the inner side of the lateral digital process, and between the contour type on the posterior border and the profile type on the stalk axis at four localities with a large sample size. Also in the frequency of the types of the stalk axis, posterior border and digital process of the baculum, independency existed among six localities. The analysis of variance showed no significant difference in the mean ratio of the baculum width to its stalk length among six localities.
Therefore, it is impossible to distinguish
E. kageus from
E. smithi by these diagnostic characters. Furthermore, I argue that it is difficult to accept the establishment of
E. kageus using the method of coefficient difference.
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