北九州市立自然史博物館に寄贈されたマダガスカル産アンモナイト

抄録

An ammonite from Madagascar has been recently donated to the Museum by Mr. Kazuo Kawakami and provided to me for study. It is called Torquatisphinctes sp. aff. T. primus Spath and described in Japanese, with illustration (Pl. 1, Fig. 1).

Remarks are given as follows: (1) It is necessary to examine the variations of numerous "species" from Madagascar and Cutch to give a final conclusion of classification. (2) Dimorphism is probably present in Torquatisphinctes and this specimen may represent a macroconch. (3) The suggested age from this specimen is the Kimmeridgian (Upper Jurassic). (4) The species can support the intimate palaeogeographical relation between Madagascar and the west coast of India in the Kimmeridgian time.