BIVALVIA. ; 9 
The variety called cylindrica or cymbiformus (fig. 3, c), is also occasionally found in 
the Coralline Crag, though by no means abundantly. It has been determined by 
British Conchologists, that this form is produced from its place of adherence being the 
stem of the seaweed, or some such cylindrical body,* while the variety /ornicata 
is said to be merely a deformity from some similar cause; this I have not yet seen 
in the fossil state. The exterior of some of the Crag specimens indicate their place 
of rest to have been upon a Bryozoon, the shell being prettily and distinctly marked by 
that animal. 
Some idea may be formed of the Protean character of this species, as no less than 
eighteen different specific names are introduced by the authors of the ‘ Hist. of Brit. 
Moll.’ into their synonyma, while these, with several others by them, considered 
as distinct, are included as mere varieties by Mr. Clark. 
2. ANOMIA ACULEATA, Miller. Tab. I, fig. 2, a—é. 
Anomta AcuLEaTa. Miill. Zool. Dan. Prod., p. 249, 1766. 
as — Mont. Test. Brit., p. 157, pl. 4, fig. 5, 1803. 
= — Brown. Brit. Conch. Ilust., pl. 34, fig. 6, 1827. 
— — S. Wood. Catalogue, 1840. 
— — Gould. Invert. Massach., p. 139, fig. 90, 1841. 
— — Philippi. En. Moll. Se., vol. ii, p. 214, t. 28, fig. 1, 1841. 
== — Thorpe. Brit. Mar. Conch., p. 123, fig. 73, 1844. 
— — Loven. Ind. Moll. Scand., p. 30. 
_ _ Dekay. Nat. Hist. New York (Zool.), p. 168, pl. 12, fig. 210. 
— srriotata. Turt. Brit. Biv., p. 233, 1822. 
— — W. Wood. Ind. Test., p. 54, pl. 11, fig. 7, 1825. 
= —_— Flem. Brit. An., p. 396, 1828. 
— — Thorpe. Brit. Mar. Conch., p. 123, 1844. 
Spec. Char. Testé suborbiculari vel ovata ; striatd, striis plurimum numerosis, radian- 
tibus, sqyuamoso-aculeatis ; umbone submarginal, levi. 
Shell suborbicular or ovate ; striated, strize generally numerous, with fine elevated 
or squamose prominences, rendering the surface rough or prickly ; umbo, submarginal, 
and smooth. 
Diameter, 4, an inch. 
Locality. Cor. Crag, Sutton, and Ramsholt. 
Recent, Mediterranean, Britain, Scandinavia, and North America. 
This species, called the prickly Anomia, is very abundant in the Coralline Crag at 
Sutton, whence all my numerous specimens were obtained. I have not yet seen it 
from the newer formations. It closely resembles the young of the preceding in most 
* This, however, was not the position of our shell, which is the upper or imperforate valve, and is 
quite flat, the lower or adherent one, was probably convex externally, and fixed to the interior of some 
cylindrical body, and to which our specimen must have acted as a lid. 
2 
