140 RECORDS OF THE AUSTRALIAN MUSEUM 



Hang's restriction of Ancyloceras was regarded by Dr. D. J. 

 Anthula 16 as unsatisfactory; although he stated his opinion that 

 a trustworthy definition of the D'Orbignyan genus could not be 

 given. 



In 1902 appeared the paper, ahead)' quoted, by Messrs. Sarasin 

 andSchondelmayer. 1 ' These authors vigorously dispute Dr. Haug's 

 definition of Ancyloceras on the grounds that it is contrary to 

 the generally admitted opinion in phylogenetic classification to 

 give importance to the characters of the terminal portion of the 

 shell in preference to the initial. They define Crioceras as con- 

 sisting of species "derived from Hoplites, which present dis- 

 jointed whorls with an inrolment sometimes crioceratic, some- 

 times ancyloceratie." The mode of enrolment emplo} r ed by 

 D'Orbigny is not of preponderating importance, nor is a group 

 classification of the species assisted by the structure of the sutures, 

 in consequence of their uniform and constant characters; on t lie 

 other hand, the sculpture of the initial whorls is a good feature 

 for differentiation into groups. 



These authors divide Crioceras ( + Ancyloceras) into seven 

 groups, each corresponding to a subgenus. For their second 

 group (or subgenus) they reserve the name Ancyloceras, with C. 

 renauxianum, D'Orb., as type, instead of A. matheronianum, 

 D'Orb., the more usually accepted type. Messrs. Sarasin and 

 Schondelmayer, whose paper is dated 1902, do not appear to have 

 had the advantage of consulting Hyatt's classification published 

 in 1900. Their second group, just referred to, contains two of 

 Hyatt's genera — Tomoceras (-4. duvalianum, D'Orb.), and Dirri- 

 moceras {A. simplex, D'Orb.). The third group, typified by Ancy- 

 loceras matherouiamivi, D'Orh., is, according to Hyatt, Ancyloceras 

 (sensu strictu) ! Lastly, the fourth group, with A. tabarelli, 

 Astier, as its representative, is more or less equivalent to Hyatt's 

 Acrioceras, of which the species named is the type. 



In 1900 appeared the first volume of Eastman's translation 1 " 

 of Zittell's ' Grundzuge der Palajontologie,' 1 '•' with the article 

 ' Cephalopoda ' revised and in a great measure rewritten 

 by the late Prof. A. H}'att, and containing the classifica- 

 tion referred to above; it is to lie regretted that this highly 



99. 



1900. 

 Svo. London. 



^'/ittel— Grundzuge der Pahuontologie (Palivozoologie) Svo. Munich and 

 Leipzig, 1S95. 



