NATJTILID^. 
149 
slightly concave slope to the point of contact with the precediDg 
whorl, which leaves two very distinct ridges upon the cast. The 
form of the section is thus, roughly speaking, hexagonal. The 
Tig. 24. 
Temnocheihis Cricki. — a, front view of the body-chamber of an imperfect speci- 
men, showing the position of the siphuncle ; b, side view, showing the 
curvature of the specimen ; c, peripheral view. Drawn from a specimen 
in the Collection. A little less than one half natural size. 
smaller extremity of the fossil shows that the sutures formed rather 
a deep, hackwardly directed sinus upon the sides of the shell, and a 
Y-shaped sinus on the periphery. The siphuncle is situated a little 
above the centre. The shell is perfectly smooth, there being nothing 
upon its surface but fine lines of growth. The aperture, which is 
almost entirely covered by the matrix, probably had a sigmoid out- 
line, with a tolerably deep peripheral emargination, judging by the 
direction of the lines of growth. 
Hem arks. This species bears a close resemblance, in its quadrate 
whorls and form of sutures, to Nautilus Tschernyscheiii, Tzwetaev \ 
but its more rapid rate of tapering and the absence of tubercles 
separate it completely from that species. . 
^ “ Cepbalopodes de la Section Superieure du Calcaire Carbonifere de la 
Eussie Centrale,” Mem. du Comite Geologique (St. Petersburg), 1888, vol. v. 
no. 3, pp. 12 and d8, pi. ii. ff. 7-10. 
