158 RECORDS OF THE AUSTRALIAN MUSEUM. 



vies in size with the large Crioceras in the Australian Museum 

 already referred to, but the entire absence of any trace of tuber- 

 culation on the latter renders a further comparison impossible. 

 It is the only instance amongst our large Crioceri of a shell 

 bearing three rows uf tubercles in advanced age ; certainly C. 

 jackii possesses the same number, but this occurs at the coin- 

 mencement of its career only. 



The tubercles are borne upon what may be termed the primary 

 costse, which at the distal end of the coil are two and a half 

 inches apart from crest to crest. On the dorsum, where some 

 trace of the test remains, they decrease very greatly in size, and 

 are there similar to the ordinary or secondary costse. The section 

 of the whorls when taken on the primary costse is octagonal, viz., 

 three angular lateral lines on each side or flank, with the truncate 

 venter and flat dorsum, but if the section is taken on the secondary 

 costai in the valleys it is simply quadrangular ; the infra-abdominal 

 line of tubercles is the largest. 



C. lampros must have attained a very large size ; the diameter 

 of the one whorl alone is twenty-one inches. 



This is the only one amongst our Crioceri that conforms to 

 Hyatt's definition of his Family Ancyloceratid*, after the type of 

 A. matheronianum, D'Orb. 



A similar arrangement of the tubercles occurs in C. thiollierei, 

 Astieiy' ;; ' and also in the smaller form 0. tabarelli, Astier. 40 



Another exotic Crioceras much resembling this species in the 

 form of the costse and again in the presence of three rows of pro- 

 minent tubercles is C. munieri, Sar. & Schon., 41 of the French 

 Neocomian. 



In the Point Charles deposit, Port Darwin, occur fragments of 

 whorls with three rows of tubercles. In this and C. lampros the 

 tubercles are confined to the larger or primary costae, and the 

 venters are more or less flattened or depressed. In one case the 

 tuberculate costse are single, 4 " 1 in the other they are double across 

 the venter, between the latter and the flank nodes, and again 

 between the latter and those along the dorsal edge, the nodes 



■' 'Astier— Ann. Sci. Phys. Nat. Soc. Nat. Agiic. Lyon, (2), iii., p. 448, 

 pi. xix., f. 7. 



1 Astier — Loc. cil., p. 449, pi. xxi., f. 9. 



1 ] Sarasin and Sch.mdelmayer — Mem. Soc. Pal. Suisse,xxix., 1902,pl.xiv., 

 f. 1. 



•±'»Etheriuge— S. Austr. Pari. Papers, 1907 (Suppl. to No. 55), 1906, p. 16, 

 pi. x., figs. 4 and 5. 



