CrpHaopopa. | UPPER PALAXOZOIC MOLLUSCA. 565 
as the periphery at base ; first lateral sinus broad, semielliptically rounded; first lateral lobe narrower than 
the first sinus, lanceolate, acuminate at the end, yery slightly passing the radial line; second lateral sinus 
resembling the first lateral lobe in size and shape; second lateral lobe larger than the rest, similar to the first 
in shape, but passing the radial line by rather more than half its width; third lateral sinus resembling the 
second in shape, but rather smaller; third lateral lobe smaller than the rest, less acutely pointed, and barely 
touching the radial line; fourth lateral sinus semielliptically pointed, a little exterior to the edge of the 
umbilicus. Diameter of average specimen four inches, proportional antero-posterior diameter of last whorl 3%, 
diameter of umbilicus , width of mouth ;5, diameter of penultimate whorl 7°. 
The siphon of this species is not distinctly visible in the specimens in the collection, one of which formed 
the originally figured type of the species. The septa are remarkable for the near similarity of the lobes, and 
sinuses (= saddles of continental writers) in size and shape; the lobes are however rather more pointed. This 
is one of the few Aganides of the carboniferous period with simple mid-lobes. 
Position and Locality—Not very uncommon in the dark carboniferous limestone of Scarlet, Isle of Man. 
AGANIDES IMPLICATUS (Phill.) 
Ref. and Syn. = Goniatites implicatus Phill. Geol. York, Vol. II. t. 19.f. 24, 25. 
Desc.—Discoid, sides gently convex, flattened, greatest thickness close to the umbilicus, which is very 
minute, or almost obsolete ; periphery very broad, obtusely rounded; surface nearly smooth, with very delicate, 
transverse strize, nearly straight on the sides near the umbilicus, slightly waved forwards near the edge of the 
periphery, and arched backwards on the middle of the periphery. Septa: mid-lobe oblong, twice as long as wide, 
trifid, the middle lobule very small, much shorter than the lateral ones, which are less than one-third the length 
of the mid-lobe ; first lateral sinus much broader than the mid-lobe, widely rounded in front, the outer line 
diverging, but the inner one (common to the mid-lobe) parallel with that of the other side ; the anterior end of 
the first lateral sinus passes nearly one-third of the length of the succeeding mid-lobe in height; first lateral 
lobe small, triangular, pointed, with converging straight sides, scarcely equalling the mid-lobe in length; second 
lateral sinus little more than half the height of the first, and passing into the umbilicus. Diameter of large 
8 
specimen one inch seven lines, diameter of umbilical depression =, width of periphery %, width of mouth at 
edge of umbilicus = (greater in smaller specimens), = at one inch three lines in diameter, #3 at eleven lines in 
diameter. 
The septa are remarkable for the parallelism of the sides of the mid-lobe and first lateral sinus on each side, 
and for the encroaching of these on each other in succeeding septa in such a way that there is often an appear- 
ance on casts of two parallel continuous spiral lines on the sides of the periphery. 
Position and Locality —Not uncommon in the carboniferous limestone of Poolwash, Isle of Man. 
Aaanipes Listert (Mart. Sp.) 
Ref. and Syn. = Oonch. Naut. Am. Listeri Martin, Pet. Derb. t. 35. f. 3. = Ammonites Listeri Sow. Min. Con. 
t. 501. f.1; de Kon. Anim. Foss. Bel. t. 51. f. 4; Phill. Geol. York. Vol. II. t. 20. f. 1.=<A. sacer 
Dumont = A. carbonarius Von Buch, Ueber. Amm. und Gon. t. 2. f. 9. 
Desc.—Globose, subdiscoid, of about five rapidly increasing whorls; sides and periphery regularly arched, very 
convex; umbilicus large, conical, deep ; mouth transversely reniform, greatest width at the edge of the umbilicus, 
which is marked with about twenty-two small rounded tubercles on each side of each whorl, from which short 
obtuse ribs extend about half-way down the umbilicus, the remainder of which is smooth; on the exterior each 
tubercle gives rise to a small bundle of two, three, or four obscure, obtuse, unequal ridges, having a broad 
shallow wave on the periphery, parallel to which are thicker constrictions on the casts, at distances of about a 
quarter of a volution; the external shell is thin, and, when preserved, shews a strong, transverse, subimbricating 
striation (about sixteen striz in two lines on large specimens, five of the internal ribs in the same space), 
crossed by some very faint, more distant, regular, spiral striz under the lens, slightly crenulating the transverse 
