VERRUCA. 43 
separated valves from the Red and Coralline Crags, collected by Mr. S. Wood. ‘The 
moveable opercular valves have not been discovered; and these are certainly much the 
most important parts for the diagnosis of the species; but the other valves are tolerably 
perfect, and are undistinguishable from recent specimens of /. Strémia ; therefore, I have 
ventured, with some hesitation, thus to name these specimens. The fossil specimens all 
belong to the common variety, having its shell longitudinally ribbed, a character not 
observed in. the four other species of the genus. Asan aid to collectors in the Crag, I have 
thought it would be more serviceable to give a drawing (fig. 9 @), from a recent specimen, 
of all the six valves, separated, but in as nearly as possible their proper relative positions, 
and likewise of the under side of the fixed scutum and tergum, than to give fac-similes of 
such valves, in themselves not perfectly characteristic, which have as yet been discovered 
fossil. 
It should be borne in mind, that of the six valves of which figures are here given, it is 
just as likely that reversed specimens from the opposite side of the body should be found, 
as these which represent valves taken from a specimen in which the left-hand scutum and 
tergum were fixed and formed part of the shell. 
2. Verruca Prisca. ‘Tab. II, fig. 10a—10c. 
Verruca Prisca. Bosquet. Monographie des Crustacés fossiles du Terrain Crét. de 
Iimbourg, Tab. 1, fig. 1—6; 1853. 
V. testé levi; seuti mobilis eristad articulart inferiore aliquanto latiore quam 
superior. | 
Shell smooth: moveable scutum, with the lower articular ridge somewhat broader than 
the upper articular ridge. 
Fossil in Chalk, Norwich, Mus. J. de C. Sowerby: ‘Systeme Senonien et Maestrichtien,’ Belgium, 
Mus. Bosquet. 
M. Bosquet has admirably figured and described the several separated valves belonging 
to this species, and I owe to his great kindness an examination of some of them. In Mr. 
J. de C. Sowerby’s collection, also, there is a single specimen (fig, 10a), attached to a 
Mollusc, with the four valves of the shell united together, but without the two moveable 
opercular valves; it cannot be positively asserted that this is the same species with that 
of M. Bosquet, but such probably is the case. The opercular valves (fig. 104, 10c) are 
necessarily figured from Belgian specimens. It is the English specimen to which [ 
alluded in the Introduction to my ‘Monograph on Fossil Lepadide.’ This species of 
Verruca is interesting, from being the only known Secondary one, but in itself it is a 
