CEPHALOrODA FR03I THE HOKKAIDO. 



TETRAGONITES Koosmaï. 



Of the species of Tetragoniles described in the following liney, 

 three luive been already described liy Jim bo. One of these — 

 Lytoceras glahrum JimbH — is considered l)y Kossmat" to belong 

 to his newly established subgenus Tetrcujonltes. He states that 

 nothing definite can Ije said about the other two — viz., L. crassum. 

 JiMBô and L. sphaerojwtum Jimbö. However, after a careful 

 examination of the types and other specimens the writer has 

 come to the conclusion, that these two should also be brought 

 under the same genus. 



TETRAGONITES GLABRUS Jijibô sp. 

 PL VIT., figs. 2 and o. 



1894. Lytoceras glabnim Jimbö : 1. c. p. 34 (180), PI. VI. 



(XXIL), figs. 2,2 a. 



1895. Lytoceras {Tetr agonîtes) glahrum Kossmat : I.e. p. 133. 

 Dimensions : — 



Dian: 

 Ileig 

 BretK 

 Widt 



1) A sj^ecimen from the Sanushibe, Prov. Iburi.(Pl. V., fig. 2). 



2) A specimen from the Opiraushibets, Prov. Teshio. 



This and the next species possess very inflated whorls in the 

 later stages of growth, and comparatively a very thin test. There- 



Diameter. 



Ileiglit of the last whorl. 

 Breadth of the last whorl. 

 Widtli of umbilicus 



100. 

 49. 



21. 



1) Kossmat: I.e. \>. 3/ (133). 



