APPENDIX. 247 
Mediterranea. In none of the descriptions which I had read of Solemya is there any allusion made to its 
having a double or divided cartilage, or to that division, which is situated within the umbonal cavity ; only 
the large triangular portion, placed on the short side of the shell, is noticed. As my casts of Solemya 
primeva exhibit the impressions of the umbonal division of the cartilage, and not those of the triangular 
portion (this last circumstance is explained by the peculiar way in which the cartilage is attached to its 
fulcra), I was induced to infer, that this fossil differed from the recent species noticed, in having the car- 
tilage undivided, and situated within the umbonal cavity. Further: from the prevailing misapplication of the 
terms anterior and posterior to the two extremities of Solemya, in consequence of its being generally under- 
stood that the cartilage, in the recent species, is situated on the posterior end, that is, on the short side,—and 
from the impressions of this structure, in the fossil species; being underneath the umbones, and consequently 
on the opposite or long side,—I was also led to infer, that the latter differed from the former, m having the 
cartilage placed within the umbonal cavity, and not behind it. That those conchologists, however, are in 
error, whose description of Solemya states, or implies, that the cartilage is situated on the posterior side of 
the valves, will be readily perceived by a reference to the figures of the animal of Solemya Mediterranea in 
Philippi’s ‘Enumeratio Molluscorum Sicilize,’ and in plate 115 of the Atlas of ‘Les Mollusques,’ accom- 
panying the ‘ Reunion’ edition of Cuvier’s ‘Regne Animal,’—which figures show the remarkable and 
singular peculiarity of one of the divisions of the cartilage placed in front of the umbones, over the oral 
apparatus, where the lunette is usually situated in other bivalves. 
I shall, in the next place, introduce a diagnosis of Solemya, which I am desirous should be substituted for 
the section on Janeia in page 177. 
Genus Solemya, Lamarck. 
Diagnosis.—Transversely elongated: equivalved: inequilateral, the posterior side being the longest: 
obtuse at the extremities. Hpidermis shining; reaching beyond the margins of the valves. Umbones 
searcely prominent. Cartilage internal; divided; one portion (the largest) situated in front of the 
umbones on two oblique lamelliform callosities or fulera, having their free margin slightly separated from 
the inner surface of the valves,—the separation containing the cartilage; the other and smallest portion 
slightly spreading over the inner surface of the valves within the umbonal cavities. Pallial line entire, and 
marginal. 
Gasteropoda (Carnivorous). 
I have elsewhere noticed (Vide London Geological Journal, vol. i, p. 11; and description of plate xv, 
lines 7 and 8) the drilled holes observable on some of the fossils described in the present Monograph, 
and which indicate the existence of Carnivorous Gasteropods during the Permian period. The following are 
the shells in which I have observed these perforations,—Bysso-arca tumida, Mytilus squamosus, Epithyris 
suffiata, and Trigonotreta multiplicata. 
Calyptrea antiqua, Howse. 
A doubtful fossil, with this name, is described as follows in the ‘ Transactions of the Tyneside Naturalists’ 
Field Club,’ vol. i, p. 242. 
“Shell small, patelliform; strongly ribbed longitudinally; margin crenulated; two deep furrows 
internally, from the apex to the margin, corresponding with two strong ribs on the outer surface. 
“In Magnesian limestone; rare. Tunstall Hill. 
“Only one small specimen of the shell has occurred. The characters noted above are very conspicuous, 
and its strong resemblance to many Calyptrea has induced us to place it in that genus.” 
