BIVALVIA. Li 
Spec. Char. WN. testa, elongato-ovatd, turgidd, tumidd, inequilaterali ; levigatd, glabra, 
margine dorsali subrecta, pedi-regione ovatd ; siphoni-regione, prelongd, subrostratd ; mar- 
gine ventrali convexd ; lunuld viv conspicud ; apicibus depressis ; marginibus integris. 
Shell elongately ovate, inflated, inequilateral, smooth and glossy; dorsal margin 
nearly straight; ventral margin convex; pedal region large, ovate; siphonal region 
obtusely pointed ; lunule inconspicuous; beaks depressed; margins smooth. 
Length, ths of an inch; height, 3ths of an inch. 
Locality. Hampstead Heath (Wethereil); Potter’s Bar, and Highgate (Hdwards). 
The peculiar distinction is the pointed or subrostrated form of the siphonal region, 
where it is slightly compressed, from which I presume it received its name, as the shell is 
otherwise rather tumid. 
6. Nucuua consors, S. Wood. Tab. XIX, fig. 7, a, 0. 
Nucuta stmitis. J. Sow. Min. Conch., vol. ii, p. 207, t. 192, figs. 3, 4, 1819. 
Spec. Char. NV. testé obovatd, transversd, subtrigonuld, turgidd, valde inequilaterali, 
obsolete radiatd, aliquantisper striis transversis decussatd ; pedi-regione prolongd, obtusa ; 
siphoni-regione rotundaté truncata ; margine ventrali convexd ; lunuld vie distinetd ; ano 
ovato in medio prominenti ; marginibus crenulatis. 
Shell transverse, obtusely ovate, roundedly trigonal, turgid, very inequilateral, obsoletely 
rayed, slightly decussated by lines of growth; pedilateral margin obtusely or roundedly 
angulated ; dorsal and ventral margins convex ; lunule indistinct; anal region slightly 
prominent; internal margins crenulated. 
Length, an inch ; height, sths of an inch. 
Locality. Highgate (Wetherell). 
Many specimens of this species are in the cabinet of Mr. Wetherell; but they are 
seldom in good condition, the greater number of them being merely casts. 
Professor Morris, in his ‘Catalogue of British Fossils,’ has rejected figs. 3 and 4, 
t. 192, ‘ Min. Conch.,’ from being identical with the Barton species figured upon the same 
plate, and Mr. Sowerby says, at p. 208, he is doubtful whether fig. 4 ought not to be 
considered a distinct species, or at least a distinct variety, implying thereby a doubt as to 
the propriety of admitting it under the name of s¢mz/is. I have, therefore, given it a new 
specific name with more confidence, having the support of the above two opinions. It 
resembles in many of its characters one or two species from the Middle Eocene, but with 
none does it appear to be truly identical. It has no distinctly marked lunule. There is 
a prominent anal region surrounded by a depression, and in those specimens which are 
best preserved the radiating striae are very distinct, decussated by lines of growth. The 
two valves are most commonly united, and many of them have been perforated by a 
zoophagous feeder. 
