57 



ON AX EXAMPLE OF ACANTHOTEUTHIS FURUSSACII, Munst., 

 FEOM THE LITHOGRAPHIC STONE OF SOLENHOFEN, BAVAEIA, 

 EXHIBITING THE BUCCAL MEMBRANE. 



By G. C. Crick, P.G.S., F.Z.S., etc., 



Of the British Museum (Natural History). 



Head lit/i January, 1898. 



PLATE IV. 



" The germ.?, Acanthoteuthis was founded by E.. Wagner and G. Miinster 

 upon small hooklets, sometimes isolated, sometimes associated with 

 more or less complete remains of the animal, which are found in the 

 Lithographic Stone of Bavaria. Miinster characterized three species 

 chiefly upon the form of these hooklets, viz., A. speciosa, A. Ferussacii, 

 and A. Lichteyisteinii, and noticed the existence of a fourth. Sub- 

 sequently Miinster referred to this genus also a number of forms 

 based principally upon the shape of the body and upon the form of 

 the internal shell, but most of these were afterwards separated by 

 A. Wagner as a new genus [Flesioteutliis). The genus AcanthoteutMs 

 is therefore restricted to such forms as Miinster described chiefly upon 

 the form of the hooks." ^ 



According to Miinster's description of the three above-mentioned 

 species, the hooklets in A. speciosa are compressed and both the 

 margins on one side bevelled ; in ^. Ferussacii they are also com- 

 pressed, but are smaller and the edge of the concave margin only is 

 bevelled; whilst in A. Lichtensteimi they. are both smaller than in 

 A. speciosa, and more nearly circular in transverse section. D'Orbigny 

 united these three species under the name A. Ferussacii ; whilst 

 Dr. A. Wagner regarded A. speciosa as a valid species, but seeing no 

 essential difference between Miinster's A. Ferussacii and A. Lichten- 

 steinii, united these under the former name. 



A. speciosa appears to be specifically distinct from A. Ferussacii, 

 but we have not been able to examine sufficient material to enable 

 us to express any opinion about the identity of A. Ferussacii and 

 A. Lichtensteinii. 



The specimen referred to in the present communication forms part 

 of the British Museum Collection (No. 39,881), and is exhibited on 

 the counterparts of a small split slab of Lithographic Stone (Upper 

 Oolite) from Solenhofen, Bavaria. It is labelled '■'AcanthoteutMs 

 Ferussacii, Miinst.," and since the hooklets of the arms certainly have 

 the form of those ascribed to that species, we adopt this name for the 

 specimen. In Miinster's type the arms were attached to a roughly- 

 shaped elongated mass representing the head and body, the former 



1 G. C. Crick, GeoL Mag., 1897, p. 1. 



