CEPHALOrODA FROIM THE HOKKAIDO. Zö 



und lieicb-elien noch zum üftern wiederholt, sie sind den Weber- 

 spulen zu verglichen, über welche die Faden sich hin und her 

 über einander windet. Was setzt das nicht fiir eine Beweglich- 

 keit der Organe voraus !" 



Of course, Qüenstedt did not know, then, that such a 

 peculiar form as the present species would occur in Japan. 



INCERTiE SEDIS. 



There are few forms of Ammonites in our fauna, more 

 interesting than the single specimen described below under the 

 name of Ammonites Koioi. Its characters agree in several re- 

 spects with Olcosiephaaus siiperstes Kossmat" which that author, 

 together with Ammonites rvdra Stoliczka,"' temporally brought 

 under the genus Olcostephantis. He, of course, acknowledged 

 the phyletical relation of these two Ammonites to Vascocevas on 

 one side and to Acanthoceras on the other, although they much 

 resemble, not only in the general aspect of their external form, 

 but also in their suture line, the lower Cretaceous and the 

 Jurassic species of the genera Olcostephanvs and Stephonoceras — 

 a good example of heterochronous homoeomorphy, a. phenomena 

 now known as often occurring in the Cephalopoda. 



Vascoceraé"^ is a genus lately proposed by P. Choffat to 

 include Ammonites intermediate between Olcostephanus and 

 Acanthoceras {3Iammites). According to this author, Ainin. 

 syperstes differs from Vascocevas in respect of the higher saddles 



1) Kossmat: I.e. p. 1?.3, pi. XVII., figs. 1 a, b, c. 



2) Kossmat: I.e. p. 20. — Stoliczka : I.e. p. 122, [il. LX. Further see Xeumaye: I.e. 

 p. 933. 



3) Choffat: Faune Crétacùjue du Portugal, II Série. P. 51. 



