Cretaceous Fossils from British Columbia. 317 



seen to be marked with fine raised lines, parallel to the 

 ribs. Sutural line unknown. 



Maximum breadth of the outer volution of the largest 

 specimen collected, nearly two inches and three-quarters. 



Hornby Island, W. Harvey, 1894 ; two specimens, one 

 with most of three volutions, and the other with the whole 

 of four volutions and a part of the fifth preserved. 



It is, perhaps, doubtful whether the distinctions 

 between Heteroceras and Anisoceras can be maintained. 

 In the one the earlier volutions are said to be always in 

 contact, while those of the other are described as separate 

 and as forming an irregular open spiral. The two speci- 

 mens from Hornby Island for which the foregoing 

 provisional name is suggested, are coiled in precisely the 

 same way as the Heteroceras Conradi of the Mesozoic 

 Fossils, 1 and differ therefrom only in their much finer ribs 

 and more particularly in the circumstance that some of 

 these ribs bear a tubercle on each side of the periphery. 

 On the other hand, the surface ornamentation of the only 

 known specimens of H Hornbyense is so like that of 

 Anisoceras Vancouver ense, that it is just possible that they 

 may prove to be specimens of the early stage of large 

 individuals of that species. 



Heteroceras perversum. (Nom. pro v.) 



Shell sinistral, but in other respects essentially similar 

 to that of the preceding species. 



Hornby Island, W. Harvey, 1894 ; a single specimen 

 about an inch and three quarters in its maximum diameter, 

 with nearly the whole of one volution remarkably well 

 preserved. 



It is not at all unlikely that the early volutions of H. 

 Hornbyense may be coiled indifferently to the right or left, 

 and if so, that this may be a mere sinistral variety of that 



1. Geological Survey of Canada, Mesozoic Fossils, vol. I., part 2 (1879), p. ICO, pi. 

 12, figs. 1-3. 



