142 MOLLUSCA FROM THE CRAG. 
Shell transverse, ovate, inequilateral, thick, and strong; ornamented with radiating 
stri, decussated by concentric ridges; a large elongated lunule; hinge with one 
cardinal tooth and two lateral teeth in each valve: umbones prominent. 
Length, + of an inch. Height, 3;ths of an inch. 
Locality. Cor. Crag, Sutton. 
This is by no means an abundant shell, and the above dimensions are to the 
full amount of my largest specimen. 
It is a pretty species, covered externally with large obtuse rays, or depressed ribs, 
they are but few in number in the young state, increasing as the shell enlarges by the 
introduction of an intermediate ray, sometimes diverging in pairs; they are crossed 
by large obtuse ridges, or thickened lines of growth, placed sometimes in pairs, 
generally more irregular; the shell is nearly oval, but the anterior side is much the 
larger of the two, the umbo is elevated, and immediately beneath it is one triangular, 
sub-bifid tooth in the right valve, with two distinct, nearly equidistant lateral teeth, 
and in the left valve are two, diverging on each side of the triangular space, for 
the reception of the one of the right valve, with two lateral teeth: the rays are 
visible within the shell, and =the muscle marks are not very deeply seated: the 
anterior one is elongated, though not strictly of that ligulate or tongue-shaped 
form so characteristic of the true Zucina. Tellina reticulata, Poli. (Lucina pecten, 
Phil., ‘En Moll. Sic.,’ p. 31, T. 3, fig. 14), slightly resembles our shell, but it has finer 
and more numerous rays, and is more orbicular. 
Some time since I sent over to M. Deshayes a few specimens of three or four 
species, thought to bear a very close resemblance to those of the Paris basin, 
requesting he would be kind enough to compare them with his own types ; and since 
the first part of my MS. had gone to press, I have received a communication from that 
gentleman, who has obligingly complied with my request. He says: “J’ai examiné 
avec la plus grande attention vos trois espéces Lucina squamosa, Erycina miliaria, and 
Nucula miliaris, avec les types qui me restait dans ma collection et il resulte pour moi 
de cet examen rép¢été un grand nombre de fois, qu’aucune de vos espéces n’est 
parfaitment identique avec celles de notre bassin Parisien. Ces espéces et les 
notres ont entre elles de grandes resemblances mes elles offrent aussi des differences 
constantes.” 
The means of determination possessed by M. Deshayes are probably sufficient 
to enable him justly to separate the Crag shell from the Older Tertiary species, and 
I have given a new name to our fossil upon such decision; and in consequence of the 
above opinion so strongly expressed, I have re-examined my own Crag specimens of 
Nucinella miliaris with what I have considered as the same species from the Paris 
basin in my own Cabinet, but with a high respect for the opinion of that able naturalist, 
I cannot reconcile myself to the belief, that the differences observable between the two 
are sufficiently prominent to justify a specific removal for the British fossil. 
