GASTEROPODA. 135 



are the prominence of the margin surrounding the umbilicus, and its elegantly 

 imbricated costae, or reflected lines of growth. The spiral strias are most distinct 

 at the outer part of the base of the shell, but traces of them may be detected on 

 the upper part of the volution between the costee. The aperture of the shell is 

 hidden in the matrix. 



2. Margarita (?) maculata. S. Wood. Tab. XV, fig. 3. 



Solaiuella maculata. £. TFood. Cat. 1842, p. 531, pi. 5, fig. 7, 10. 

 Turbo moniliferus. Nyst. Itech. Coq. foss. d'Anvers 1835, p. 27. 

 Solarium turbinoides. Nyst. Coq. foss. de Belg. p. 370, pi. 26, fig. 7, 1844. 

 — Lyell. Iu Quart. Journ. Geol. Soc. p. 555, 1845. 



M. Testa trochoided, vel solariformi, tenui et fragili ; spird depressd ; anfractibus 

 quit) que, subcgUndracis, crenulatis ; cingulis tribus vel quatuor, ornatis ; suturis profuudis 

 canalicidalis ; aperturd rotundatd ; umbilico magno, granulato. 



Shell depressedly conical, subtrochiform, or rather solariform ; spire slightly 

 elevated ; apex rather obtuse ; volutions four or five, subcylindrical, with three, 

 sometimes four, rugose or crenulated bands or ridges, the upper one of which is 

 the most prominent ; base rough, striated or ridged, with a large open umbilicus, 

 and a carinated and granulated edge ; shell nacreous. 



Axis, \ of an inch nearly ; diameter, § . 



Locality. Cor. Crag, Sutton. 



This shell is given as a Miocene fossil of America by Mr. Lyell. Small specimens 

 and fragments are by no means rare from the Crag ; but a shell of the size figured 

 is very difficult to obtain in a perfect condition, from its extreme fragility. It 

 appears, from the form of the shell, to be intermediate between Solarium and 

 Trochus, probably nearly related to the latter ; and closely resembling Margarita. 

 It has three large and obtuse ridges or carinas upon the upper and outer half of the 

 volution, though only two are visible upon the spire. The upper one is largest, 

 and may be said to be divided into three, which are crenulated or granulated by 

 elevated obtuse lines of growth, and there are upon the base about half a dozen 

 ridges or elevated concentric lines ; the largest, surrounding the umbilicus, is 

 roughly crenulated, like a Solarium, and the volutions are visible beneath up to the 

 apex. In well-preserved specimens the shell is covered with very fine spiral striae. 

 A deep and broad canal is formed near the suture by the elevation of the large 

 upper keel, and there are the remains of coloured blotches, from which character 

 its name was given. 



The Belgian shell, M. Nyst informs me by letter, is the same as the British 

 fossil ; though the figure in the work of that gentleman is much more elevated 

 than any of my specimens. 



