AQ BRITISH SILURIAN BRACHIOPODA. 
nearly straight and slightly indented, or presenting a very gentle convex curve; beak 
short and very obtusely acuminated; valves moderately convex. Surface marked with 
numerous more or less deeply indented concentric lines of growth. ‘Two specimens 
measured— 
Length 13, width 12, depth 5 lines. 
SIN IIONS CH SITS GINS T 
Ods. Unfortunately, M. Marie Rouault figures none of the many Brachiopoda he 
has described in the seventh and twentieth volumes of the ‘ Bulletin ;’ and, although his 
descriptions are generally carefully worded, it is well known that a figure is indispensable 
with reference to new species, and that no description will compensate for the omission.’ 
Therefore, without being able to compare our Budleigh Salterton specimens with those found 
in Brittany, it is difficult to be absolutely certaim with reference to the present identification. 
The French paleontologist, moreover, informs us that his shell is of an almost circular 
form, a little longer than wide; and I do not know whether our British specimens are 
sufficiently so to answer to the French description, which would agree more closely with 
the shell we have described further on as Z. Salter; but as the shell has been so described 
and figured by Mr. Salter, I will for the present abide by his decision.’ 
L. Hawket, as well as all its congeners, appears to have been liable to malformation, 
or to present a greater or lesser depression in one of its valves, together with an indenta- 
tion or emargination of its front, under which condition is the specimen which Mr. Salter 
thought might be identified with Rouault’s Zingula Brimonti ; several examples, however, 
subsequently found by Mr. Vicary, clearly showed that this was not the normal condition 
of a species, and they may therefore be united with the above. 
As to geological age, it is the same as that of Z. Leswewrt and L. Rouaulti, namely, 
the horizon of the Armorican sandstone of Rouault, which he places in the Lower Silurian. 
Linevuta Lesvrurt, Rouauit. Pl. I, figs. 1—11. 
Lingua Lesururti, Marie Rouault. Bulletin Soc. Geol. France, vol. vii; 2nd series, 
p. 727, 1850. 
_ -—~ Salter. Quarterly Journal Geol. Soc., vol. xx, p. 292, pl. xvii, 
fig. 1, 1863. 
1 So necessary is this found to be, that the Geological Society of France within the last few years 
determined not to publish in their ‘ Bulletin’ the description of any new species unaccompanied by a figure. 
2M. Rouault describes his Lingula Hawkei in the following words: ‘“ Longueur, 42 millimetres 
[20 lines]; largeur, 38 millimétres [18 lines]; épaisseur, 20 millimétres [16 lines]. Coquille de forme 
presque arrondie: un peu plus longue que large; plus développée en avant ; renflée vers le haut ; s’amin- 
cissant vers le bord: sans cétes 4 sa surface: lignes d’accroissement trés-marquées. Se distingue de 
L. dubia, D'Orb., par sa forme plus allongée et son plus grand développement; et de L. guadrata, Eich., 
par sa largeur, qui est plus grande en avant, et beaucoup moindre en venant gagner la charniére. 
Localité: Guichen [Brittany ].”’ 
