828 
SUPPLEMENT. 
by him in the triangulare-gvovi^ ” must remain doubtful until the 
initial parts of their shells shall have been observed. Such a dis- 
covery, however, is not likely to be of much value if the question 
cannot be settled upon the evidence afforded by the adult shells. 
Though these forms have hitherto been placed in the genus Ortho- 
ceras, yet their subtriangular section, close and undulating septa, 
and usually nummuloidal and marginal siphuncles, are all characters 
which mark them off very distinctly from that already unwieldy 
genus. If, therefore, it should be deemed advisable to found a 
separate family for the “ ^nan^wZare-group,” it would bear the name 
JoveUaniidce, 
Jovellania Murrayi, Billiugs, sp. 
1857. Orthoceras Murrayi, BiUings, Geol. Surv. of Canada, Rep. of 
Progr. for the years 1853-1856, p. 332. 
1863. Orthoceras Murrayi, Billings, Geol. of Canada, Appendix, 
p. 950. 
SiJ. Char. “ Section subelliptical or obscurely triangular, tapering 
at the rate of one line aud a third to the inch, from a lateral dia- 
meter of thirteen lines ; ventral aspect the broader ; flattened or 
but slightly convex; dorsal side most convex along the centre, 
giving to the section a subtriangular shape ; lateral diameter greater 
than the dorso-ventral in the proportion of about eleven to thirteen ; 
siphuncle cylindrical, one sixth of the greatest diameter of the 
fossil, situated near the ventral margin. The septa on the ventral 
side make a strong curve towards the apex ; they are distant from 
one seventh to one tenth of an inch. In a specimen three and a 
half inches in length and thirteen lines wide at the largest end, in 
the first inch of the smaller extremity there are not quite se'^'eu 
septa ; in the next inch the same number, in the third nine, and in 
the half inch five. Another specimen shows ten septa to one inch, 
at a diameter of thirteen and a half lines, and in a third there are 
nine at a diameter of one inch ; they are moderately convex. An 
artificial section through five of the chambers shows that the 
siphuncle is cylindrical, and that the septa, at the point of their 
contact with it, are bent suddenly towards the apex [the septal 
necks are here meant] ; the surface, which is not well shown, 
appears smooth. . . {Billings.) 
RemarTcs. There are some features observable in the fine examples 
of this species in the British Ifuseum which are not touched upon 
in BiUings’s description of the fossil. These consist of numerous 
well-marked longitudinal ridges, which are seen upon the cast ; also 
