]^L ATE 35. 
FIG. 3. 
CONCHYLIOLITHUS N. Ammonites (Listen) 
anfractibus subinsertis, ambitu depresso-convexo lato: 
costis transversis bifidls, disco craterasformi costato: 
tuberculorum serie marginal!, dissepimentis sinuatis. 
S. p. , 
A fossil shell. The original a Nautilus. Spiral, depres- 
sed. (Syst. Gen. 6. Fam. Ammonita.) Volutions slightly 
inserted. Ambit depressed, convex, broad, with transverse, 
bifid, slender, equal, close ribs. Disk crateraiform, ribbed; 
surrounded by a single, marginal row of small rounded tu- 
bercles, from which the ribs take their rise. The dissepi- 
ments or partitions of the chambers sinuate; the siphuncle 
placed beneath, close on the back of each succeeding volu- 
tion ; its structure not ascertained. 
A common species : it is found in most of our limestone 
tracts, particularly near Eyem and Middleton. 
