310 



is compressed oval, the abdomen broader than the dorsum, but the centro- 

 dorsal (*) diameter is longer than the transverse. 



" The siphuncle is nearer the centre, being ventrocentren. The neanic, 

 or perhaps an ephebic stage has slight annulations or raised lines of 

 growth, judging from the marks on the section. This is labelled as coming 

 from the white limestone of Large Island. 



" There is no impressed zone at any stage observed. The ephebic stages 

 have a whorl similar to that of Barrandeoceras convolvans in the neanic 

 stage, but the abdomen is broader." Hyatt, op. cit. supra. 



(3.) Barrandeoceras subcostulatum, Whiteaves. 



Plate 38. The only figure. 



Barrandeoceras subcostulatum Norn. prov. Whiteaves 1898. Ottawa Naturalist, vol. 



XII, p. 121. 



Cfr. Lituites convolvans, Hall (non Hisinger) 1847. Pal. N.York, vol. I, p. 53, pi. 



13, figs. 2 and 2 a. 

 Hortholus Americanui, dt'Ovhigay . .\9oO. Prodr. de Paleont., tome 1, p. 1 (non 



Bortholus convolvans, Montfort, 1808). 

 Lituites Americanus, S. A. Miller. .1889. N. Amer. Geol. and Palseont., p. 442. 

 Barrandeoceras convolvans, Hyatt. . 1894. Prcc. Amer. Phil. Soc, vol. XXXII 



p. 451. 

 „ S. A. Miller. 1897. N. Amer. Geol. and Palseont., 



Second Appendix, p. 771. 



Original description of Barrandeoceras subcostulatum. " Shell consisting 

 of about two gyroceran volutions which are coiled loosely on the same 

 plane, but nowhere in close contact, and gradually becoming jnore 

 eccentric, the outer one slightly compressed both above and below, so 

 that the outline of a transverse section near the aperture would be 

 broadly elliptical, and the dorsoventral diameter a little greater than the 

 lateral. 



" Surface of the test distinctly costulate, though in the only specimen 

 that the writer has seen, the ribbing is most clearly defined on the inner 

 volution, where it consists of rather distant but irregularly disposed, small, 

 thin, acutely angular and slightly flexuous transverse ribs or ridges, 

 which are generally much narrower than the very shallow depressions 

 between them, and marked with numerous minute striations parallel to 

 the ribs. Sutures of the septa not clearly indicated ; shape and relative 

 position of the siphuncle unknown." 



Black River limestone at Wolfe Island near Kingston, the fine specimen, 

 figured, which is fully four inches in its maximum diameter, and which 

 was presented to the Museum of the Survey by Professor James Fowler 

 in 1888. 



* Presumably a typographical error for ventrodorsal. 



