60 BRITISH SILURIAN BRACHIOPODA. 
Var. Woopwarpu, Salter. PI. V, figs. 7, 8. 
OxsoLus Woopwarpu, Salter, MS. (Mus. P. Geology). 
Shell transversely oval; posterior marginal almost straight (?) ; surface marked with 
concentric lines of growth. Length 22, width 27 lines. 
Oés. Certain undetermined differences are observable in an imperfect cast; but 
the material at command is very incomplete. 
Position and Locality. Wenlock limestone, Dormington Wood, Woolhope, and 
Wenlock shales near Dudley. Both specimens may be seen in the Museum of Practical 
Geology. 
Genus—OBOLELLA, Billings, 1861. 
Ref. ‘ Geology of Canada,’ “ Paleozoic Fossils,” vol. i, p. 7, 1861. 
Not having been able to study the interior characters in this genus, all I can do is to 
reproduce Mr. Billings’ description. 
“ Generic Characters. Shell ovate, circular, or sub-quadrate, convex or plano-convex. 
Ventral valve with a false area, which is sometimes minute, and usually grooved for the 
passage of the peduncle. Dorsal valve either with or without an area. Muscular 
impressions in the ventral valve four, one pair in front of the beak near the middle or in 
the upper half of the shell, and the others situated one on each side, near the cardinal 
edge. Shell calcareous ; surface concentrically striated, sometimes with thin, expanded, 
lamellose ridges. 
“In general form these shells somewhat resemble Odo/us, but the arrangement of the 
muscular impressions is different. In Odolus the two central scars have their smaller 
extremities directed downwards and converging towards each other, but in this genus 
the arrangement is exactly the reverse.” 
Six Canadian species are described by Mr. Billings; but, unfortunately, the shells 
are small, and the figures showing the interior markings not sufficiently distinct. Nor do 
our British specimens help us out in this particular. Messrs. Meek and Hayden, while 
describing their Odolella nana, observe that “since seeing Mr. Billings’ figures of his 
genus Odolella, recently published, they are fully satisfied that he is right in separating 
these shells from the genus Odolus.” 
It is not, however, perfectly certain that any of our hitherto discovered British species 
agree with Mr. Billings’ genus, although two or three have been referred to it. 
