Gasreropopa. } UPPER PALAZOZOIC MOLLUSCA. 543 
Genus. NATICOPSIS (A/°Coy) 1844. See page 301. 
Syn. = Naticodon de Ryckholt (1852). 
The operculum (which I have seen several times) differs entirely from that of any of the family Naticida, 
and agrees with Ampullaria in being concentric, and not spiral. A specimen of V. Phillipsi (M‘Coy) is in the 
_ British Museum, shewing the operculum with the laminze more distinct than in my old figure. Very recently 
(Mén. Acad. Roy. Bruxelles, 1852) M. de Ryckholt forms of these shells a genus which he names Naticodon, 
from the existence of a tooth on the internal face of the pillar-lip, which I have not as yet seen. 
NATICOPSIS AMPLIATA (Phill. Sp.) 
Ref. and Syn. = Natica ampliata Phill. Geol. York. Vol. II. t. 14. f. 21 and 24; de Kon. Anim. Foss. 
Bel. t. 42. f. 2. 
Dese —Obliquely trigono-ovate, wider than long; spire and upper third of body-whorl flattened together, 
of two yolutions, not strongly defined, very rapidly enlarging towards the mouth; base (or front) convex, nar- 
rowed conoidally ; mouth very large, rotundato-trigonal ; pillar-lip broad, callous, flat. Surface crossed by close, 
regular, equal, thread-like, obtuse strice (fifteen in two lines), crossed under the lens by microscopic spiral striz ; 
substance of the shell thick. Width of small specimen ten lines, proportional length 4, length of mouth or 
last whorl %, width of mouth 4, space between last and penultimate suture 4. 
The flattened spire, extremely wide mouth, and regular filiform striation, distinguish this species very readily 
from the others of the genus. The strize deserve the name of minute ribs from their regularity and distinctness 
even to the naked eye. 
Position and Locality—Not very uncommon in the carboniferous limestone of Kendal; rare in the carboni- 
ferous sandstone with Lepidodendra at Shap Toll-bar. 
NaTicopsis PLIctstRIA (Phill. Sp.) 
Ref. and Syn. = Natica plicistria Phill. Geol. York. Vol. II. t. 14. f. 25; Portk. Geol. Rep. t. 31. f. 6, 7. 
2+. elongata Phill. Geol. York. t. 14. f. 28. 
Desc,—Ovate, globose when young, obliquely elongate when old; apical angle about 105° to 115°, but 
cannot be taken well from the convexity of the outline; spire very short, obtuse, of two and a half gently convex 
whorls, rather abruptly rounded towards the upper sutures, which latter are sometimes strongly defined and 
nearly rectangular, sometimes strongly imbricating; body-whorl evenly convex in young specimens, but with age 
gradually acquiring a wide, shallow concavity nearly along the middle, above which the surface is obtusely 
convex to the imbricating (or occasionally sub-canaliculate) sutures, and below which it arches rapidly to the 
very convex base; pillar-lip thick, callous, flattened, and slightly concave in front, sharp-edged, arched 
gradually into the front margin; outer lip thin except at its posterior junction with the suture; substance of 
the shell extremely thick. Surface with fine irregular lines of growth, abruptly changing near the sutures into 
fine, sharp, equal, obliquely-arched, thread-like strize, separated by rather wider concave sulci, forming a 
plicistriate border about two lines wide on the body-whorl, and extending over rather more than half the space 
between the sutures on those of the spire (fourteen or fifteen in a space of two lines), Length of adult 
5 0 
specimen three inches, proportional width 4, length of mouth 4, space between last and penultimate sutures =. 
g 86 
Proportions of specimens one inch long, width =, length of mouth =, space between last and penultimate 
sutures =>. 
The colouring is often preserved in this species, and shews as two or more rows of large, oblong, brown 
and whitish blotches. From the great thickness of the shell the casts seem umbilicated, and have the whorls 
separated by deeply excavated sutures: the internal casts are often marked with more regular (though faint 
and obtuse) striz than the exterior. I agree with M. de Koninck in thinking the N. elongata may be referred 
[rasc. 111. ] 4A 
