A new genus, with a new species, of the talpine mole is described from the island of Uotsuri-jima in the Senkaku Islands, the Ryukyu Islands, under the name of Nesoscaptor uchidai. This species retains the dental formula of I3/2 + C1/1 + Pm3/3 + M3/3=38, which consists of one fewer pair of teeth in the lower incisors than in Scaptochirus with 40 teeth. The skull has very short and broad rostrum, broad maxillary portion, and very large molars all of which are also characteristic to Scaptochirus. Except for the dental and skull characters probably induced by the reduction of teeth, the other characters such as the feature of tympanic bulla, the ear bones consisting of malleus with a broad and long triangular cavum lamina and of short incus, and the pelvic girdle with two pairs of dorsal foramina are principally common to those of Euroscaptor and Mogera. Thus the new species is a composite of some other talpine moles. Retaining two cusps on the last lower premolar is a remarkable character which has never been found in any of the other talpine genera.

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Reproduction and social organization of nursery colonies of M. n. bombinus were investigated by the banding-recapture method for long periods. Maternity colonies were composed almost entirely of pregnant females. Females reached sexual maturity in the first autumn. They produce annually one young per litter, and most of them continued every year until the age of seven. The reproductive rate in yearling females was as high as 90.5%, while that per year in all adult females more than one year of age averaged 88.8%. Females tended to return to their natal sites in successive years, though first-year returns were 50.2% for yearling females. Such a low returning rate indicates high mortality or dispersal rate for the first year of life. The returning or survival rate of adult females was remarkably high. There was little individual exchange among nursery colonies ; only 9.5% of adult females were immigrants. Thus, the primary unit of the nursery colony is related female groups coming of maternal lines.

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To clarify the relationships between 10 inbred strains of rats (ACI, BN, DON, IS, LEW, TM, W, WAG, WKYO, and ZI) and to identify each strain, principal component and discriminant analyses were carried out using 13 mandible measurements. (1) Principal component analysis revealed that mandibles were large in BN, LEW, and TM ; small in ACI, IS, and DON. The mandibles of W and WAG were shorter and fairly higher. The shape of the muscular process is acute and projecting posteriorly in BN, IS, and WAG ; obtuse and less projecting in LEW, TM, and WKYO. The morphometrical relationships between strains by the principal component analysis accorded with the Mahalanobis distance between strains based on the same mandibular measurements. (2) Discriminant analysis showed the probability of erroneous discrimination to be 0% (0/204) in both sexes. These results indicate that strain differences are found in the size and shape of mandibles, and that multivariate analysis using mandible measurements is available for strain identification of laboratory rats.

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The karyotype of E. smithii with the large X chromosome (X^L), captured in Toyama Prefecture, was studied using conventional, G-and C-banding techniques. It was almost equal to the karyotype of specimens with the normal X chromosome, except for the X^L chromosome having the lengthened short arm. From detailed comparisons of the patterns by the above three stainings between the X^L and normal X chromosomes, the following facts were clarified : their arm ratios were different ; the normal X chromosome possessed the euchromatic short arm, while the lengthened short arm of the X^L chromosome was entirely heterochromatic and did not have the euchromatic portion in the proximal region. Therefore, the X^L chromosome is formed by both pericentric inversion and subsequent duplication of constitutive heter-ochromatin. In addition, judging from the facts that specimens carrying the X^L chromosome were trapped from two different localities in Toyama Prefecture, and that a male having a similarly large X chromosome has been found also in Ishikawa Prefecture (Tsuchiya, 1981), the distribution of the population characterized by the X^L chromosome appears to be restricted to the Hokuriku District.

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A mass mortality of sika deer (Cervus nippon) population occurred on Kinkazan Island in northern Japan in the spring of 1984, which followed an unusual cold winter. We collected a sample of 240 deer skulls. All deer were aged and sexed except some fawns. The sex ratio of >1 year old deer was 50: 50, but was skewed toward males compared with the sex ratio obtained in the population census in 1983. The oldest age at death was 12.5 years for males and 15.5 years for females. The frequency was low for young age classes. A relative cumulative frequency curve was constructed to examine the age-specific mortality pattern. The curves of both sexes suggested that mortality was relatively high for fawns and low for adult and prime-aged animals, and that mortality was higher and life span was shorter for males than for females.

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