52 
NAUTILOIDEA. 
1858. Lituites {TrocholitTins) antiquissimus, Schmidt, Archiv fiir die 
Naturkunde, Liv-, Ehst- und Kurlands, p. 198. 
? 1 860. Clymenia rarospira, Eichwald, Lethaea Rossica, vol. i. Seconde 
Section de Tancienne Periode, p. 1302, tab. l. fF. 2 a, 6 ; C a-c, 
not ff. 1, 3. 
1867. Discoceras antiquissimum, Barrande, Syst. Sil. de la Boheme, 
vol. ii. pt. i. p. 177. 
\_Not 1861. Lituites antiquissimus, Roemer, Die Fossile Fauna der 
Silurischen Diluvial-Geschiehe von Sadewitz, p. 62, Taf. vi. ff .2 a-gi] 
Sp. Char. Shell of large size, umbilicated on both sides, with five 
closely contiguous volutions, the body-chamber deeply emarginate on 
the convex side. The section is rather obscurely subquadrate. 
The septa are numerous, their distance apart on the sides of the 
shell being about 3 lines where the shell-diameter is 13 or 14 lines ; 
the sutures form a shallow sinus on each side and a distinct lobe at 
the superior lateral angles. The siphuncle is situated close to the 
concave border of the shell. The ornaments of the test consist of 
prominent, oblique, widely separated annulations, which do not, 
however, leave any mark upon the cast ; they form a shallow back- 
wardly-directed sinus upon the periphery. The annulations and 
their interspaces are covered with very fine and close-set imbrica- 
ting lines. 
Remarks. To this species I have referred an example which has 
some of the test remaining, in which the ribbing is obscurely trace- 
able, while the finer ornaments are well preserved in one or two 
places. The character of the septation is well seen, and it agrees 
perfectly with that of Eichw aid’s species. 
Horizon. Or/7ioc€r«s-Limestone (=Arenig). 
Locality. Ozersky(?) (Esthonia), Russia. 
Represented in the Collection by a single example. 
Trocholites iuliformis, Salter, sp. 
1865. Lituites iulifor7nis, Salter, in Palaeont. of Niti in the Northern 
Himalaya, being Descriptions and Figures by J. W. Salter and H. 
F. Blanford of the Palaeozoic and Secondary Fossils collected by 
Colonel R. Strachey, R.E., p. 14, pi. ii. f. 2. 
Sp. Char. Discoid, and very much flattened ; our solitary speci- 
men an inch and three quarters in diameter, having at least four or 
five contiguous but not embracing whorls, which are squarish in 
section, about two thirds as deep from back to front as wide; some- 
what flattened on the sides,, sloping to the umbilical margin, very 
blunt and flat on the back, and gently concave on the inner edge. 
Surface with undulating sharp unequal stride of growth. The 
