« 
148 MOLLUSCA FROM THE CRAG. 
It has been justly remarked, by Messrs. Forbes and Hanley, that in consequence 
of its anomalous character, this shell has been bandied about and placed in many 
different genera, but generally with a doubt respecting its true position; the deep 
palleal sinus indicated the possession of somewhat elongated or at least projecting 
siphons, thereby differing from the animals of true Zucina, in which genus some 
authors had placed it, where from its dental characters and general appearance it 
seemed most entitled to be situated. They have, however, removed it from among the 
family Zucinide, and placed it in the Veneride, in consequence of the deeply sinuated 
form of the palleal impression; and this view of its connection seems to have been 
taken by other Malacologists. 
The possession of a sinus in the impression of the mantle mark is a distinction, 
we have elsewhere seen, in all probability sufficient for the removal of a shell with 
such a character out of a genus, where others have the mantle mark perfectly entire, 
but there is no sufficient reason in that alone that it should be removed to any very 
distant position. Its general affinities appear more in connection with those of Lucina 
than with those of Venus, differing from the former only in the aberrant character of a 
prolongation in the siphonal tubes, bearing the same relationship to Lwcina, or rather 
to Diplodonta, that Leda does to Nucula, or as Adacna to Cardium : \ have, therefore, again 
ventured to remove it from among the Vener:de to what appears a more correct position. 
The name of J/ysta was proposed in MS. for a genus by Dr. Leach, in which the 
Venus undata, Penn., was placed; and this name has been published by Lamarck in his 
‘Hist. Nat. des An. sans Vert.,’ t. v, p. 543, 1818, thereby giving it a status in regard 
to time; and considering that sufficient for its right to priority, it was adopted by 
myself in ‘The Catal. of Crag Shells, for the Crag species, but another well-identified 
shell belonging to the genus Diplodonta had also attached to it the same generic 
name, and this was published by Brown, in 1827. It is not now possible to say which 
of the two species was intended as the type of his proposed new genus, and therefore, 
to unravel the difficulty, or rather to cut the Gordian knot, the authors of Lucinopsis 
have, perhaps wisely, rejected in toto the name of J/ysia. 
This appears a very natural genus, although very few species are yet known 
either in a recent or fossil state. Two or three shells from the Greensand Formation, 
figured and described under the name of THETIS, somewhat resemble it in the dental 
characters, but they have a deeper and more angulated sinus in the mantle mark. 
1. Lucinopsts Lasonxatril, Payraudeau. Tab. XI, fig. 14, a—e. 
Ency. Method., p. 272, fig. 2, a—é, 1800. 
Venerupis Lagonkarrit. Payr. Cat. Moll. delle de Corse, p. 36, pl. 1, figs. 12, 13, 1826. 
— — Desh, 2d ed. Lam., t. vi, p. 164, 1835. 
Venus LupinorpEs. Myst. Rech. Coq. Foss. Prov. d’Any., pl. 11, No. 41, pl. 3, fig. 14. 
Mysta ornata. SS. Wood. Catalogue, 1840. 
TELLINA LupINoIDES. Nyst. Coq. Foss. de Bélg., p. 111, pl. 5, fig. 4, a—e, 1844. 
— ? articutata. Id. - - = pall Os ple6; ties Ica; 6: 
