LINGULID A. 35 
British Species (?) not yet sufficiently made out. 
16. Lingula Bechei, Salter, MS. 21. Lingula minima, Sow. 
ee — squamosa, Holl. 22. —  pygmeea, Salter. 
18. —_ parallela, Phillips. 23. —_ brevis, Portlock. 
19. —_ longissima, Pander. 24. —_ obtusa, Hall (M‘Coy). 
20. — _ curta (Conrad), M‘Coy = young 25. —  lepis (Lingulella), Salter. 
L. attenuata. 
There are also one or two other uncertain forms ; hence it is very probable, as 
already stated, that several of these ten last-named species (?) may, when better known, 
prove to be either synonyms, varieties, or variations in form of some of the fifteen first 
named. I have, however, considered it desirable, in the present state of our knowledge, 
to give short descriptions as well as figures of the entire series, so that the student may 
form his own opinion upon the matter, and not have to depend upon my views alone. 
Lineuxa Lewis, Sow. PI. III, figs. 1—6. 
Lingua Lewisit, Sow. Silurian System, pl. vi, fig. 9, 1839; and Siluria, pl. xx, fig. 5, 
1859. 
— — Dav. Bull. Soc. Géol. France, vol. v, 2nd ser., p. 333, pl. iii, fig. 
44, 1848. 
— — MCoy. British Paleozoic Fossils, p. 253, 1852. 
Spec. Char. Subquadrate, oblong, longer than wide ; sides almost parallel ; front very 
slightly rounded ; beaks obtusely angular, the slopes rarely straight ; valves almost equally 
deep, the convexity very small; surface nearly smooth, or marked with numerous con- 
centric raised lines or ridges of growth, and here and there by more deeply indented 
striz. 
Length 14, width 10, depth 23 lines. 
Oés. This well-known species is easily distinguishable from LZ. granulata and L. tenud- 
granulata by its surface not being reticulated. Good interiors or internal casts are 
- sometimes obtained, of which representations will be found in our plate. 
Position and Locality. This species is stated to have been found in the Woolhope 
beds, Wenlock shale and limestone, Lower Ludlow and Aymestry limestone; but is most 
abundant in the last-named formation. It occurs in the Lower Ludlow rock of Mortimer’s 
Cross, Aymestry, Herefordshire ; also in the Aymestry rock at Sedgley, between Dudley 
and Wolverhampton; at Mary Knoll, and many other localities in the Ludlow promontory. 
Prof. M‘Coy mentions its occurrence in the Lower Ludlow rock of Leintwardine, 
Shropshire, and in other places in the same county. Mr. Lightbody states that he 
finds LZ. Lewisii in the Upper Ludlow series, but rarely; and near the top of that 
series abundance of another form, rather smaller, which he would be disposed to regard 
