22 AKT.. 7. — öwTANAKA: 



apart from one anotHer ; anterior two plates each with a small 



plate in front. Four or five rugose plates behind dorsal fin; 



three rugose plates behind anal fin ; two large rugose plates in 



front of anal. The skin between rows of plates soft and smooth. 



A large plate at scapular part ; directly behind it a small plate. 



Cheek with fine stellate prickles. Skin covered rather sparsely 



with very small stellate prickles, no large prickles among these. 



First two-thirds of base of anal below posterior part of base of 



dorsal. Distance from posterior end of base of ventral to a point 



vertical through origin of dorsal, a little less than the distance 



from posterior end of base of dorsal to caudal base. 



The species besides, being much larger in size than Acipenser 



liiikadoi, differs from the latter in having a much greater number 



of dorsal and lateral plates, smaller and less prickles ou the 



skin, and much smaller prickles on cheek. The species differs 



also from Acijyenser hikuchii in having much shorter dorsal, a 



somewhat more prickly skin, much more numerous dorsal and 

 lateral plates, and a slightly finer prickles on cheek. 



The type of the species, 212 cm. long to caudal base, was 



captured seven miles off Ukedohama, Province of Iwaki, with 



the plaice gill-net on May 21*^ 1905. It is now preserved in 



the stuffed state in the museum of the Zoological Institute. It 



is numbered 955. Tvv;o, more or less imperfect skin of the same 



species purchased of a fish-merchant in Tokyo, are contained in 



the Imperial Museum of Tokyo. 



